UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D. C. 20549

FORM 10-K

For the fiscal year ended June 30, 2005

OR

For the transition period from                      to                     

Commission File No. 1-4982

PARKER-HANNIFIN CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (216) 896-3000

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No ¨.

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of Registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K ¨.

Indicate by check mark whether the Registrant is an accelerated filer (as defined in Rule 12b-2 of the Exchange Act).

Yes x     No ¨.

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨ No x

The approximate aggregate market value of the voting stock held by non-affiliates of the Registrant as of December 31, 2004, excluding, for purposes of this computation only, stock holdings of the Registrant’s Directors and Officers: $9,066,622,254.

The number of Common Shares outstanding on July 31, 2005 was 119,687,052.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the following documents are incorporated by reference:

PARKER-HANNIFIN CORPORATION

FORM 10-K

Fiscal Year Ended June 30, 2005

PART I

ITEM 1. Business. Parker-Hannifin Corporation is a leading worldwide full-line manufacturer of motion control products, including fluid power systems, electromechanical controls and related components. Fluid power involves the transfer and control of power through the medium of liquid, gas or air, in hydraulic, pneumatic and vacuum applications. Fluid power systems move and position materials, control machines, vehicles and equipment and improve industrial efficiency and productivity. Components of a simple fluid power system include one or more pumps which generate pressure, one or more valves which control the fluid’s flow, one or more actuators which translate the pressure from the fluid into mechanical energy, one or more filters to insure proper fluid condition and numerous hoses, couplings, fittings and seals. Electromechanical control involves the use of electronic components and systems to control motion and precisely locate or vary speed in automation and aerospace applications. In addition to motion control products, the Company also is a leading worldwide producer of fluid purification, fluid and fuel control, process instrumentation, air conditioning, refrigeration, electromagnetic shielding and thermal management products and systems. Also, through Astron Buildings (“Astron”), the Company designs and manufactures custom-engineered buildings.

The Company also manufactured and marketed specialty chemical products and maintenance service equipment through the Wynn’s Specialty Chemical Group until the Company divested this business in December 2004.

The Company was incorporated in Ohio in 1938. Its principal executive offices are located at 6035 Parkland Boulevard, Cleveland, Ohio 44124-4141, telephone (216) 896-3000. As used in this Report, unless the context otherwise requires, the term “Company” or “Parker” refers to Parker-Hannifin Corporation and its subsidiaries.

The Company’s investor relations internet website address is www.phstock.com. The Company makes available free of charge on or through its website its annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and any amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as soon as reasonably practicable after filing or furnishing such material electronically with the Securities and Exchange Commission.

The Board of Directors adopted a written charter for each of the committees of the Board of Directors. These charters, as well as the Company’s Code of Ethics, Guidelines on Corporate Governance Issues and Independence Standards for Directors, are posted and available on the Company’s investor relations internet website at www.phstock.com under the Corporate Governance

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page. Shareholders may request copies of these corporate governance documents, free of charge, by writing to Parker-Hannifin Corporation, 6035 Parkland Boulevard, Cleveland, Ohio 44124-4141, Attention: Secretary, or by calling (216) 896-3000.

The Company’s manufacturing, service, distribution and administrative facilities are located in 36 states and in 47 foreign countries. Its motion control technology is used in products of its three principal business Segments: Industrial; Aerospace; and Climate & Industrial Controls. The products are sold as original and replacement equipment through product and distribution centers worldwide. The Company markets its products through direct-sales employees, independent distributors, sales representatives and builder/dealers. Parker products are supplied to approximately 400,000 customers in virtually every significant manufacturing, transportation and processing industry. For the fiscal year ended June 30, 2005, total net sales were $8,215,095,118; Industrial Segment products accounted for 72% of net sales, Aerospace Segment products for 17%, Climate & Industrial Controls Segment products for 10% and Other Segment products for 1%.

Markets

Motion control systems are used throughout industry in applications which include moving materials; controlling machines, vehicles and equipment; and positioning materials during manufacturing processes. Motion control systems contribute to the efficient use of energy and improve industrial productivity.

The approximately 400,000 customers who purchase the Company’s products are found throughout virtually every significant manufacturing, transportation and processing industries. No single customer accounted for more than 3% of the Company’s total net sales for the fiscal year.

Major markets for products of the Fluid Connectors, Hydraulics, Automation and Seal Groups of the Industrial Segment are agricultural machinery, analytical instrumentation, aerospace, automotive, construction machinery, electronic equipment, energy, oil and gas, fabricated metals, food production, information technology, industrial machinery, pulp and paper, machine tools, marine, medical devices, mining, mobile equipment, chemicals and chemical processing, robotics, semi-conductor equipment, telecommunications, textiles, transportation and every other major production and processing industry. Major markets for products manufactured by the Instrumentation Group of the Industrial Segment are power generation, oil and gas exploration, petrochemical and chemical processing, pulp and paper, and semi-conductor manufacturing. Major markets for products of the Filtration Group of the Industrial Segment are industrial machinery, mobile equipment, diesel engines, process equipment, marine, aviation, environmental and semi-conductor manufacturing. Sales of Industrial Segment products are made to original equipment manufacturers and their replacement markets.

Aerospace Segment sales are made primarily to original equipment manufacturers in the commercial, military and general aviation markets and to end users for maintenance, repair and overhaul.

Products manufactured by the Climate & Industrial Controls Segment are used principally in commercial and industrial refrigeration systems, residential and commercial air conditioning systems, mobile air conditioning systems, and equipment and industrial fluid control markets. Sales of the

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Climate & Industrial Controls Segment are made to original equipment manufacturers and their replacement markets.

In the Other Segment, Astron produces pre-engineered single and multi-story industrial and other commercial buildings throughout Europe.

Principal Products, Methods of Distribution and Competitive Conditions

Industrial Segment. The product lines of the Company’s Industrial Segment consist of systems and components of motion control. The Fluid Connectors Group manufactures a broad range of connectors, including hydraulic, industrial and thermoplastic hose and fittings, tube fittings, quick disconnects, and plastic tubing and fittings which control, transmit and contain fluid. The Hydraulics Group produces hydraulic components and systems for builders and users of industrial and mobile machinery and equipment, such as cylinders, accumulators, rotary actuators, valves, motors and pumps, hydrostatic steering units, power units, integrated hydraulic circuits, electrohydraulic systems, digitally controlled fan-drive systems, and power take-off equipment. The Automation Group supplies pneumatic and electromechanical components and systems. Pneumatic products include pneumatic valves, air preparation units, pneumatic actuators, vacuum products, pneumatic logic systems, and structural extrusions. Electromechanical products include human-machine interface hardware and software; industrial PCs; single and multi-axis stand-alone and bus-based controllers; rotary and linear servo motors; rotary and linear stepper motors; analog and digital stepper and servo drives; precision gearheads, ballscrew, belt, and linear motor driven positioning tables; electric rod-style and rodless cylinders; and gantry robots. The Seal Group manufactures static and dynamic sealing devices, including o-rings, extruded and lathe-cut products, custom molded shapes, and combination and dynamic seals; gaskets and packings, which insure leak-proof connections; rubber and plastic boots and bellows; electromagnetic interference shielding; and thermal management products. The Filtration Group manufactures filters, systems and instruments to monitor and to remove contaminants from fuel, air, oil, water and other fluids and gases, including hydraulic, lubrication and coolant filters; process, chemical and microfiltration filters; compressed air and gas purification filters; lube oil and fuel filters; fuel conditioning filters; fuel filters/water separators; cabin air filters; intake air filters; and nitrogen and hydrogen generators and condition monitoring devices. The Instrumentation Group manufactures high quality critical flow components for process instrumentation and ultra-high-purity applications, including fittings, valves, regulators and PTFE products.

Industrial Segment products include custom units which are engineered and produced to original equipment manufacturers’ specifications for application to a particular end product and standard items. Both custom and standard products are also used in the replacement of original motion control system components. Industrial Segment products are marketed primarily through field sales employees and approximately 8,200 independent distributors.

Aerospace Segment. Principal products of the Company’s Aerospace Segment are hydraulic, fuel and pneumatic systems and components used on commercial and military airframe and engine programs.

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The Aerospace Segment offers complete hydraulic and primary flight control systems that include hydraulic, electrohydraulic and electromechanical components used for precise control of aircraft rudders, elevators, ailerons and other aerodynamic control surfaces and utility hydraulic components such as reservoirs, accumulators, selector valves, electrohydraulic servovalves, thrust-reverser actuators, engine-driven pumps, motor pumps, nosewheel steering systems, electromechanical actuators, engine controls and electronic controllers. The Aerospace Segment also designs and manufactures aircraft wheels and brakes for general aviation and military markets.

The Aerospace fuel product line includes complete fuel systems as well as components such as fuel transfer and pressurization controls; in-flight refueling systems; fuel pumps and valves; fuel measurement and management systems; center of gravity controls; engine fuel injection atomization nozzles, manifolds and augmentor controls; and electronic monitoring computers.

Pneumatic components include bleed air control systems, pressure regulators, low-pressure pneumatic controls, engine starter systems, engine bleed control and anti-ice systems, and electronic control and monitoring computers.

Aerospace Segment products are marketed by the Company’s regional sales organization and are sold directly to manufacturers and end users.

Climate & Industrial Controls Segment. The principal products of the Company’s Climate & Industrial Controls Segment are refrigeration and air conditioning systems and components and fluid control process systems and components for use primarily in the mobile and stationary refrigeration and air conditioning industry.

The Climate & Industrial Controls Segment manufactures components and systems for use in industrial, residential, commercial, mobile air conditioning and refrigeration systems and other applications, including pressure regulators, solenoid valves, expansion valves, filter-dryers, gerotors and hose assemblies. The Climate & Industrial Controls Segment products are marketed primarily through field sales employees and independent distributors and wholesalers.

Other Segment. The products of the Company’s Other Segment are custom-engineered buildings which are designed and manufactured by Astron.

Astron’s pre-engineered single and multi-story buildings serve as factories, warehouses, aircraft hangars, indoor athletic facilities, automobile showrooms, offices and supermarkets. Astron’s custom-engineered buildings are marketed primarily through builder/dealers and field sales employees.

On June 3, 2005, the Company entered into an agreement with Lindab AB to sell all of the outstanding shares of Astron subject to customary closing conditions. The divestiture closed on August 31, 2005.

Competition. All aspects of the Company’s business are highly competitive. No single manufacturer competes with respect to all products manufactured and sold by the Company and the degree of competition varies with different products. In the Industrial Segment, the Company competes

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on the basis of product quality and innovation, customer service, manufacturing and distribution capability, and competitive price. The Company believes that, in most of the major markets for its Industrial Segment products, it is one of the principal suppliers of motion control systems and components.

In the Aerospace Segment, the Company has developed alliances with key customers based on the Company’s advanced technological and engineering capabilities, superior performance in quality, delivery, and service, and price competitiveness, which has enabled the Company to obtain significant original equipment business on new aircraft programs for its systems and components and, thereby, obtain the follow-on repair and replacement business for these programs. The Company believes that it is one of the primary suppliers in the aerospace marketplace.

In the Climate & Industrial Controls Segment, the Company competes on the basis of product quality and innovation, customer service, manufacturing and distribution capability, and competitive price. The Company believes that it is one of the principal suppliers in the climate and industrial controls marketplace.

In the Other Segment, the Company competes on the basis of product quality and performance and competitive price. The Company believes that through Astron it is one of the primary suppliers of steel buildings in Europe.

Research and Product Development

The Company continually researches the feasibility of new products and services through its development laboratories and testing facilities in many of its worldwide manufacturing locations. Its research and product development staff includes chemists, mechanical, electronic and electrical engineers and physicists.

Research and development costs relating to the development of new products or services and the improvement of existing products or services amounted to $165,331,275 in fiscal year 2005, $143,023,429 in fiscal year 2004 and $122,013,485 in fiscal year 2003. These amounts include both costs incurred by the Company related to independent research and development initiatives as well as costs incurred in connection with research and development contracts. Customer reimbursements included in the total cost for each of the respective fiscal years 2005, 2004 and 2003 were $34,756,921, $48,434,734 and $29,561,273.

Patents, Trademarks, Licenses

The Company owns a number of patents, trademarks and licenses related to its products and has exclusive and non-exclusive rights under patents owned by others. In addition, patent applications on certain products are now pending, although there can be no assurance that patents will be issued. The Company is not dependent to any material extent on any single patent or group of patents.

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Backlog and Seasonal Nature of Business

The Company’s backlog at June 30, 2005 was approximately $2,356,071,162 and at June 30, 2004 was approximately $2,202,928,002. Approximately 87% of the Company’s backlog at June 30, 2005 is scheduled for delivery in the succeeding twelve months. The Company’s business generally is not seasonal in nature.

Environmental Regulation

The Company is subject to federal, state and local laws and regulations designed to protect the environment and to regulate the discharge of materials into the environment. Among other environmental laws, the Company is subject to the federal “Superfund” law, under which the Company has been designated as a “potentially responsible party” and may be liable for cleanup costs associated with various waste sites, some of which are on the U.S. Environmental Protection Agency Superfund priority list.

As of June 30, 2005, the Company is involved in environmental remediation at 31 manufacturing facilities presently or formerly operated by the Company and has been named as a “potentially responsible party,” along with other companies, at two off-site waste disposal facilities and three regional sites.

The Company believes that its policies, practices and procedures are properly designed to prevent unreasonable risk of environmental damage and the consequent financial liability to the Company. Compliance with environmental laws and regulations requires continuing management effort and expenditures by the Company. Compliance with environmental laws and regulations has not had in the past, and, the Company believes, will not have in the future, material effects on the capital expenditures, earnings, or competitive position of the Company.

As of June 30, 2005, the Company has a reserve of $20,612,112 for environmental matters which are probable and reasonably estimable. This reserve is recorded based upon the best estimate of costs to be incurred in light of the progress made in determining the magnitude of remediation costs, the timing and extent of remedial actions required by governmental authorities and the amount of the Company’s liability in proportion to other responsible parties.

The Company’s estimated total liability for the above mentioned sites ranges from a minimum of $20,612,112 to a maximum of $66,516,528. The actual costs to be incurred by the Company will be dependent on final delineation of contamination, final determination of remedial action required, negotiations with federal and state agencies with respect to cleanup levels, changes in regulatory requirements, innovations in investigatory and remedial technology, effectiveness of remedial technologies employed, the ultimate ability to pay of the other responsible parties, and any insurance or third party recoveries.

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Energy Matters and Sources and Availability of Raw Materials

The Company’s primary energy source for each of its business segments is electric power. While the Company cannot predict future costs of such electric power, the primary source for production of the required electric power will be coal from substantial, proven coal reserves available to electric utilities. The Company is subject to governmental regulations in regard to energy supplies both in the United States and elsewhere. To date, the Company has not experienced any significant disruptions of its operations due to energy curtailments.

Steel, brass, aluminum, elastomeric and thermoplastic materials and chemicals are the principal raw materials used by the Company. These materials are available from numerous sources in quantities sufficient to meet the requirements of the Company.

Employees

The Company employed 50,638 persons as of June 30, 2005, of whom approximately 22,292 were employed by foreign subsidiaries.

Business Segment Information

The Company’s net sales, segment operating income and identifiable assets by business segment and net sales and long-lived assets by geographic area for the past three fiscal years, as set forth on pages 13-16 to 13-17 of Exhibit 13 hereto, are incorporated herein by reference.

Acquisitions and Divestitures

During fiscal 2005, the Company completed several acquisitions and the divestiture of the Wynn’s Specialty Chemical Group. The description of these transactions, as set forth on pages 13-23 to 13-24 of Exhibit 13 hereto, is incorporated herein by reference.

ITEM 1A. Executive Officers of the Company

The Company’s Executive Officers are as follows:

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Mr. Washkewicz has been Chairman of the Board of Directors since October 2004; Chief Executive Officer since July 2001; and a member of the Board of Directors since February 2000. He was the President from February 2000 to October 2004; and Chief Operating Officer from February 2000 to July 2001.

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Mr. Vande Steeg has been the President since October 2004; a member of the Board of Directors since August 2004; and Chief Operating Officer since October 2003. He was Executive Vice President from October 2003 to October 2004; Senior Vice President from August 2002 to October 2003; Operating Officer from January 2002 to October 2003; Corporate Vice President from January 2002 to August 2002; Vice President from September 1995 to January 2002; and President of the Seal Group from 1987 to January 2002.

Mr. Myslenski was named Executive Vice President – Sales, Marketing and Operations Support effective in October 2003. He was Senior Vice President from August 2002 to October 2003; Operating Officer from October 2001 to October 2003; Corporate Vice President from July 2001 to August 2002; Vice President from October 1997 to July 2001; and President of the Fluid Connectors Group from July 1997 to July 2001.

Mr. Pistell was elected as Executive Vice President – Finance and Administration in April 2005 and has been Chief Financial Officer since April 2003. He was Vice President – Finance and Administration from April 2003 to April 2005; a Vice President from October 2001 to April 2003; and Treasurer from July 1993 to April 2003.

Mr. Banks was elected as a Vice President in October 2001 and named President of the Hydraulics Group effective in October 2003. He was President of the Instrumentation Group from July 2001 to November 2003; Vice President – Operations of the Climate & Industrial Controls Group from January 2001 to July 2001; and General Manager of the Skinner Valve Division from August 1997 to January 2001.

Mr. Barker was elected as a Vice President in April 2003 and named President of the Aerospace Group effective in March 2003. He was Vice President-Operations of the Aerospace Group from April 1996 to March 2003.

Mr. Bond was elected as a Vice President in July 2000 and named President of the Fluid Connectors Group effective in March 2005. He was President of the Automation Group from April 2000 to February 2005.

Mr. Dennis was elected as a Vice President in October 2001 and as Controller effective in July 1999.

Mr. Droxner was elected as Vice President and named President of the Seal Group effective in January 2002. He was President of the Seal Group Europe from July 1999 to January 2002.

Mr. Eline was elected as Vice President – Chief Information Officer effective in August 2002. He was Vice President – Information Technology International from July 2000 to August 2002.

Ms. Huggins was elected as a Vice President and Treasurer in April 2003. She was Vice President and Controller of the Filtration Group from June 1999 to April 2003.

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Mr. Kashkoush was named Corporate Vice President – Worldwide Sales and Marketing in October 2003. He was Vice President from July 2000 to October 2003 and President of the Hydraulics Group from February 2000 to October 2003.

Mr. Maxwell was elected as Vice President – Technology and Innovation in July 2003. He was Vice President – Engineering and Innovation from January 2003 to July 2003; Business Unit Manager of the Fluid Control Division from July 2002 to January 2003; and Engineering Manager of the Racor Division from July 1998 to July 2002.

Mr. Serbin was elected as Vice President – Human Resources effective in May 2005. He was Vice President – Human Resources of the Fluid Connectors Group from October 2003 to April 2005 and Vice President – Human Resources of the Hydraulics Group and the Automation Group from July 2000 to October 2003.

Mr. Sherrard was elected as a Vice President in November 2003 and named President of the Automation Group effective in March 2005. He was the President of the Instrumentation Group from November 2003 to February 2005 and General Manager of the Automation Actuator Division from May 2000 to November 2003.

Mr. Williams was elected as a Vice President and named President of the Instrumentation Group effective in March 2005. He was Vice President – Operations of the Hydraulics Group from November 2003 to February 2005; General Manager, Global Services of GE Transportation Systems (producer of rail locomotive) from October 2002 to November 2003 and General Manager, Global Sourcing and Components of GE Lighting (light bulbs and lighting systems) from November 1999 to October 2002.

ITEM 2. Properties. The following table sets forth the principal plants and other materially important properties of the Company and its subsidiaries. Leased properties are indicated with an asterisk. A “(1)” indicates that the property is occupied by the Company’s Industrial Segment, a “(2)” indicates that the property is occupied by the Company’s Aerospace Segment, a “(3)” indicates that the property is occupied by the Company’s Climate & Industrial Controls Segment, and a “(4)” indicates that the property is occupied by the Company’s Other Segment.

UNITED STATES

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FOREIGN COUNTRIES

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The Company believes that its properties have been adequately maintained, are in good condition generally and are suitable and adequate for its business as presently conducted. The extent of utilization of the Company’s properties varies among its plants and from time to time. The Company’s restructuring efforts over the past several years have brought capacity levels closer to present and anticipated needs. Although capacity has been reduced over the last fiscal year, most of the Company’s material manufacturing facilities remain capable of handling additional volume increases.

ITEM 3. Legal Proceedings. None.

ITEM 4. Submission of Matters to a Vote of Security Holders. None.

PART II

ITEM 5. Market for the Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

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ITEM 6. Selected Financial Data. The information set forth on page 13-45 of Exhibit 13 hereto is incorporated herein by reference.

ITEM 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations. The information set forth on pages 13-2 to 13-14 of Exhibit 13 hereto is incorporated herein by reference.

ITEM 7A. Quantitative and Qualitative Disclosures About Market Risk. The Company enters into forward exchange contracts and costless collar contracts to reduce its exposure to fluctuations in foreign currencies. The total carrying and fair value of open contracts and any risk to the Company as a result of these arrangements is not material to the Company’s financial position, liquidity or results of operations. The Company has entered into two interest rate swap agreements for a total notional amount of EUR 300 million. The swap agreements expire in November 2005 and effectively protect the Company against adverse interest rate changes in the EURO bond market and have been designated as a

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hedge against the Company’s anticipated refinancing of its EURO Notes that are due in November 2005. The fair value of the interest rate swap agreements was a liability of approximately $12 million as of June 30, 2005, which has been recorded in the Consolidated Balance Sheet. The net payment or receipt under the swap agreements will be recognized as an adjustment to interest expense over the term of the EURO Notes anticipated to be issued in November 2005. A 100 basis point change in the EURO bond rates specified in the interest rate swap agreements would change the fair value of the swap agreements by approximately $24 million.

The Company’s debt portfolio contains variable rate debt, inherently exposing the Company to interest rate risk. The Company’s objective is to maintain a 60/40 mix between fixed rate and variable rate debt thereby limiting its exposure to changes in near term interest rates. A 100 basis point increase in near term interest rates would increase annual interest expense on variable rate debt by approximately $320,511.

For further discussion see the Significant Accounting Policies Footnote on page 13-22 of Exhibit 13 hereto and incorporated herein by reference.

ITEM 8. Financial Statements and Supplementary Data. The information set forth on pages 13-15 to 13-41 of Exhibit 13 hereto is incorporated herein by reference.

ITEM 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure. Not applicable.

ITEM 9A. Controls and Procedures. The Company carried out an evaluation, under the supervision and with the participation of the Company’s management, including the Company’s principal executive officer and principal financial officer, of the effectiveness of the Company’s disclosure controls and procedures as of the end of the fourth fiscal quarter of fiscal year 2005. Based on this evaluation, the principal executive officer and principal financial officer, have concluded that the Company’s disclosure controls and procedures are effective in all material respects, to ensure that information required to be disclosed in the reports the Company files and submits under the Securities Exchange Act of 1934 is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms.

Management’s Report on Internal Control over Financial Reporting set forth on page 13-42 of Exhibit 13 hereto is incorporated herein by reference. The Report of Independent Registered Public Accounting Firm set forth on pages 13-43 and 13-44 of Exhibit 13 hereto is incorporated herein by reference.

There has been no change in the Company’s internal control over financial reporting during the quarter ended June 30, 2005 that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

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ITEM 9B. Other Information. On August 29, 2005, the Management Development and Compensation Committee of the Board of Directors of the Corporation approved a target award under the Corporation’s 2006 Target Incentive Bonus Plan to Robert P. Barker, one of the Corporation’s named executive officers, and certain other executive officers. Mr. Barker’s target bonus is $80,000 subject to the terms and conditions of the 2006 Target Incentive Bonus Plan attached hereto as Exhibit 10(n) and incorporated herein by reference. The four other named executive officers have received a target bonus award, subject to shareholder approval of a Section 162(m) qualified bonus plan.

PART III

ITEM 10. Directors and Executive Officers of the Registrant. Information required with respect to the Directors of the Company is set forth under the caption “Election of Directors” in the definitive Proxy Statement for the Company’s 2005 Annual Meeting of Shareholders to be held October 26, 2005 (“2005 Proxy Statement”) and is incorporated herein by reference. Information with respect to the executive officers of the Company is included in Part I hereof under the caption “Executive Officers of the Company”. The information set forth under the captions “Audit Committee Financial Expert” and “Report of the Audit Committee” in the 2005 Proxy Statement is incorporated herein by reference.

The information set forth under the caption “Section 16(a) Beneficial Ownership Reporting Compliance” in the 2005 Proxy Statement is incorporated herein by reference.

The Company has adopted a code of ethics that applies to its Chief Executive Officer, Chief Financial Officer and Controller. The Code of Ethics is posted on the Company’s investor relations internet website at www.phstock.com under the Corporate Governance page. Any amendments to, or a waiver from, a provision of the Company’s Code of Ethics that applies to its Chief Executive Officer, Chief Financial Officer or Controller will also be posted at www.phstock.com under the Corporate Governance page.

ITEM 11. Executive Compensation. The information set forth under the captions “Compensation of Directors” and “Executive Compensation” in the 2005 Proxy Statement is incorporated herein by reference.

ITEM 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters. The information set forth under the captions “‘Change in Control’ Severance Agreements with Officers” and “Principal Shareholders of the Corporation” in the 2005 Proxy Statement is incorporated herein by reference. The information set forth under the caption “Equity Compensation Plan Information” in the 2005 Proxy Statement is incorporated herein by reference.

ITEM 13. Certain Relationships and Related Transactions. The information set forth under the caption “Certain Relationships and Related Transactions” in the 2005 Proxy Statement is incorporated herein by reference.

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ITEM 14. Principal Accountant Fees and Services. The information set forth under the captions “Audit Fees,” “Audit-Related Fees,” “Tax Fees,” “All Other Fees” and “Audit Committee Pre-Approval Policies and Procedures” in the 2005 Proxy Statement is incorporated herein by reference.

PART IV

ITEM 15. Exhibits and Financial Statement Schedules.

The financial statements and schedule listed in the accompanying Index to Consolidated Financial Statements and Schedules are filed or incorporated by reference as part of this Report.

The exhibits listed in the accompanying Exhibit Index and required by Item 601 of Regulation S-K (numbered in accordance with Item 601 of Regulation S-K) are filed, furnished or incorporated by reference as part of this Report.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized.

September 2, 2005

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Pursuant to the requirements of the Securities Exchange Act of 1934, this Report has been signed below by the following persons on behalf of the registrant and in the capacities and on the date indicated.

Signature and Title

DONALD E. WASHKEWICZ, Chairman of the Board of Directors and Chief Executive Officer; DANA A. DENNIS, Principal Accounting Officer; DUANE E. COLLINS, Director; WILLIAM E. KASSLING, Director; ROBERT J. KOHLHEPP, Director; PETER W. LIKINS, Director; GIULIO MAZZALUPI, Director; KLAUS-PETER MÜLLER, Director; CANDY M. OBOURN, Director; HECTOR R. ORTINO, Director; ALLAN L. RAYFIELD, Director; JOSEPH M. SCAMINACE, Director; WOLFGANG R. SCHMITT, Director; DEBRA L. STARNES, Director; MARKOS I. TAMBAKERAS, Director and NICKOLAS W. VANDE STEEG, Director.

Date: September 2, 2005

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PARKER-HANNIFIN CORPORATION

INDEX TO CONSOLIDATED FINANCIAL STATEMENTS AND SCHEDULES

Individual financial statements and related applicable schedules for the Registrant (separately) have been omitted because the Registrant is primarily an operating company and its subsidiaries are considered to be wholly-owned.

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PARKER-HANNIFIN CORPORATION

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS

FOR THE YEARS ENDED JUNE 30, 2003, 2004 and 2005

(Dollars in Thousands)

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Exhibit Index

Shareholders may request a copy of any of the exhibits to this Annual Report on Form 10-K by writing to the Secretary, Parker-Hannifin Corporation, 6035 Parkland Boulevard, Cleveland, Ohio 44124-4141.