Exhibit 99.1

PARKER EARNINGS ACCELERATE WITH RECORD SALES AND CASH FROM OPERATIONS

Cleveland, Ohio: July 29, 2004 – Parker Hannifin Corporation (NYSE: PH) today marked new records in sales and cash flow for fiscal-year 2004, as sales topped $7 billion for the first time in the company’s 86-year history, and cash from operations reached a record $662.4 million, surpassing last year’s result of $557.5 million. This year’s record cash from operations was achieved even with the company’s discretionary contribution to its retirement and benefits plans of approximately $146 million, compared with $108 million contributed last year.

For the full year, Parker posted a 76-percent increase in net income, at $345.8 million, or $2.91 per diluted share. Revenues reached a record $7.11 billion, up 11 percent, including a 5.6-percent increase in organic volume. Last year, the company earned $196.3 million, or $1.68 per diluted share, on sales of $6.41 billion. The current year’s results include a five-cent divestiture gain and a reduction of nine cents per diluted share in realignment costs, compared with a four-cent divestiture gain and a reduction of 16 cents per diluted share in realignment costs last year.

Fourth-quarter net income for the period ended June 30, 2004 was up 156 percent, at $125.5 million, or $1.05 per diluted share, on sales of $1.99 billion, compared with last year’s quarterly income of $49.1 million, or 42 cents per diluted share, on sales of $1.66 billion. Included in the current quarter’s earnings is a five-cent divestiture gain and a two-cent reduction from realignment costs, while last year’s earnings reflected a four-cent divestiture gain and a reduction of six cents per share in realignment costs. Revenue growth in the current quarter includes a 15-percent increase in organic volume, a two-percent increase from currency translation and three-percent growth from acquisitions not reflected in the prior-year comparison.

“With the broad based recovery of all our industrial markets, and aerospace at the beginning of a rebound, our growth engine is firing on all cylinders,” said Parker CEO Don Washkewicz. “The recovery didn’t really start

1

to pick up until January, so we’ve only had the wind at our backs for half a year. Yet our margins are up dramatically, inventories remain lean and cash flow has never been stronger. We are executing our Win Strategy, and as long as this recovery is sustained, we see a lot more growth potential in our business.

“Our message to Parker employees is to keep up the great work. Our goal is to maintain the gains we worked so hard to achieve, and extend them – by executing our strategic initiatives, staying lean and focused – and shifting growth into high gear. Today, we’re winning more competitive bids on our systems and portfolio strength, global expansion, and innovation exceeding our customers’ expectations.”

Operating Results

Sales and operating income were up in all of the company’s segments, with an overall 109-percent increase in operating income for the fourth quarter, and up 45 percent for the full year.

The North American Industrial units led the improvement, with operating income up 230 percent in the fourth quarter, and 98 percent for the year. Quarterly operating income was $114.3 million on sales of $867.4 million, for a return on sales of 13.2 percent, compared with a 4.8-percent margin last year. For the year, North American Industrial operating income was $306.9 million on revenues of $3.09 billion, for an operating margin of 9.9 percent, up from 5.5 percent last year.

The International Industrial businesses posted fourth-quarter operating income of $55.9 million, up 138 percent, on sales of $565.1 million, yielding a 9.9-percent return on sales for the quarter, compared with 5.5 percent last year. The most significant margin improvements were made in Europe, despite additional realignment costs this year. In all of 2004, the international businesses recorded operating income of $159.6 million, on sales of $1.97 billion, for an 8.1-percent operating margin, compared with 6.1 percent the prior year.

Parker Aerospace sales grew 11 percent during the quarter, to $307.6 million, with $40 million in operating income, improving its operating margin to 13.0 percent, compared with 12.3 percent a year ago. Full-year sales were up 2.8 percent to $1.14 billion, while operating income was $141.8 million, for a 12.4 percent return on sales in 2004, versus 14.2 percent last year.

In the Climate & Industrial Controls business, fourth-quarter operating income was $22.4 million, on sales of $189.3 million, an 11.8 percent return on sales, compared with 10.5 percent a year ago. The business generated full-year operating income of $71.8 million on sales of $671.2 million, a 10.7-percent return on sales, compared with 9.5 percent last year.

In the Other segment, comprised of the Wynn Specialty Chemical and Astron units, quarterly operating income was $9.5 million on $63.5 million in sales, for an operating margin of 15.0 percent, compared with 8.0

2

percent last year. Annual operating income was $22.1 million on $233 million in sales, an operating margin of 9.5 percent, compared with 5.5 percent a year ago.

Outlook

Parker cited a positive outlook for fiscal-year 2005, noting an expectation for continued expansion in its diverse markets, with some possible tempering in heavy-duty trucks and semiconductors.

“As our markets continue to recover, we feel we have positioned Parker to gain a greater share of business in core and emerging markets where we have an unrivaled breadth of products and bring added engineering value, especially in aerospace, mobile, refrigeration, life sciences and clean-energy markets such as wind power and fuel cells,” said Washkewicz.

The company projected earnings for fiscal-year 2005 to mark a new record, ranging from $3.30 to $3.70 per diluted share. In the first quarter, earnings are expected to range between 70 and 80 cents per diluted share, reflecting the company’s typical pattern of earnings momentum, with more of the year’s earnings occurring in the second half.

In addition to the information provided herein, Parker advises shareholders to note order trends, for which the company makes a disclosure several business days after the conclusion of each month. This information is available on the company’s investor information web site, at www.phstock.com.

NOTICE OF CONFERENCE CALL: Parker Hannifin’s conference call and slide presentation to discuss its fiscal fourth-quarter results is available to all interested parties via live webcast at 10 a.m. ET, on the company’s investor information web site, at www.phstock.com. To access the call, click on the “Live Webcast” link. From this link, users may also complete a pre-call system test and register for e-mail notification of future events and information available from Parker.

With annual sales of more than $7 billion, Parker Hannifin is the world’s leading diversified manufacturer of motion and control technologies and systems, providing precision-engineered solutions for a wide variety of commercial, mobile, industrial and aerospace markets. The company employs more than 48,000 people in 44 countries around the world. For more information, visit the company’s web site at www.parker.com, or its investor information site at www.phstock.com.

Forward-looking statements contained in this and other written and oral reports are made based on known events and circumstances at the time of release, and as such, are subject in the future to unforeseen uncertainties and risks. All statements regarding future performance, earnings projections, events or developments are forward-looking statements. It is possible that the future performance and earnings projections of the company and individual segments may differ materially from current expectations, depending on economic conditions within both its industrial and aerospace markets, and the company’s ability to achieve anticipated benefits associated with announced realignment activities, strategic initiatives to improve operating margins, and growth initiatives. A change in economic conditions in individual markets may have a particularly volatile effect on segment projections. Among the other factors which may affect future performance are: changes in business relationships with and purchases by or from major customers or suppliers, including delays or cancellations in shipments; uncertainties surrounding timing, successful completion or integration of acquisitions; threats associated with and efforts to combat terrorism; competitive market conditions and resulting effects on sales and pricing; increases in raw-material costs that cannot be recovered in product pricing; and global economic factors, including currency exchange rates, difficulties entering new markets and general economic conditions such as interest rates. The company makes these statements as of the date of this disclosure, and undertakes no obligation to update them.

3

PARKER HANNIFIN CORPORATION - JUNE 30, 2004

CONSOLIDATED STATEMENT OF INCOME

Note: Certain prior period amounts have been reclassified to conform to the current year presentation.

CONSOLIDATED BALANCE SHEET