FOR IMMEDIATE RELEASE Exhibit 99.1

Media Contact:
Steve Zivanic
QLogic Corporation
408.667.8039
steve.zivanic@qlogic.com

Investor Contact:
Simon Biddiscombe
QLogic Corporation
949.389.7533
simon.biddiscombe@qlogic.com

QLOGIC REPORTS SECOND QUARTER
RESULTS FOR FISCAL YEAR 2010

ALISO VIEJO, Calif., October 21, 2009—QLogic Corp. (Nasdaq:QLGC), a leading supplier of high performance network infrastructure solutions, today announced its second quarter financial results for the period ended September 27, 2009.

Second Quarter Highlights

• Net revenue: $131.5 million.

• Net income: $16.2 million GAAP, $25.1 million non-GAAP.

• Net income per diluted share: $0.14 GAAP, $0.21 non-GAAP.

• Cash generated from operations: $31.6 million.

• Cash and investment securities: $340.4 million as of September 27, 2009.

Financial Results

Net revenue for the second quarter of fiscal 2010 was $131.5 million compared to $171.2 million in the same quarter last year. Revenue from Host Products was $94.0 million during the second quarter of fiscal 2010 compared to $119.7 million in the same quarter last year. Revenue from Network Products was $24.5 million during the second quarter of fiscal 2010 compared to $29.8 million in the same quarter last year. Revenue from Silicon Products was $9.6 million during the second quarter of fiscal 2010 compared to $15.7 million in the same quarter last year.

Net income on a GAAP basis for the second quarter of fiscal 2010 was $16.2 million, or $0.14 per diluted share, compared to $27.2 million, or $0.20 per diluted share, for the second quarter of fiscal 2009. Net income on a non-GAAP basis for the second quarter of fiscal 2010 was $25.1 million, or $0.21 per diluted share, compared to $45.2 million, or $0.34 per diluted share, for the second quarter of fiscal 2009.

“We are pleased with our strong financial performance during the second quarter, which was driven by a 7% sequential increase in revenue over our prior fiscal quarter. Our revenue performance, combined with effective operating expense management, yielded results that exceeded our guidance,” said H. K. Desai, chief executive officer, QLogic. “We are cautiously optimistic given the signs of stability and early indicators of recovery we are experiencing in our business. We are encouraged by the improvements we experienced in order trends and shipments during the second quarter and believe we are well positioned to experience continued improvement in financial results.”

QLogic uses certain non-GAAP financial measures to supplement financial statements based on GAAP. A summary of these non-GAAP financial measures and a reconciliation of each non-GAAP financial measure to the most directly comparable GAAP financial measure, as well as a description of the reasons that management believes that these non-GAAP financial measures provide useful information to investors and the additional purposes for which management uses these non-GAAP financial measures is presented in the accompanying financial schedules.

QLogic’s fiscal 2010 second quarter conference call is scheduled for today at 2:00 p.m. Pacific Time (5:00 p.m. Eastern Time). H.K. Desai, chief executive officer, and Simon Biddiscombe, senior vice president and chief financial officer, will host the conference call. The call is being webcast live via the Internet at http://ir.qlogic.com and www.earnings.com. Phone access to participate in the conference call is available at (719) 325-4751, pass code: 9843815.

The financial information that the company intends to discuss during the conference call will be available on the company’s website at http://ir.qlogic.com for twelve months following the conference call. A replay of the conference call will be available via webcast at http://ir.qlogic.com for twelve months.

About QLogic

QLogic (Nasdaq: QLGC) is a global leader and technology innovator in high performance networking, including adapters, switches and ASICs. Leading OEMs and channel partners worldwide rely on QLogic products for their data, storage and server networking solutions. QLogic is a NASDAQ Global Select company and is included in the S&P 500. For more information, visit www.qlogic.com.

Disclaimer — Forward-Looking Statements

This press release contains statements relating to future results of the company (including certain beliefs and projections regarding business trends, signs of stability and indicators of recovery, improvement in order trends and shipments, and position to experience continued improvement in financial results) that are “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995. Such forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected or implied in the forward-looking statements. The company advises readers that these potential risks and uncertainties include, but are not limited to: declines in information technology spending levels; potential fluctuations in operating results; gross margins that may vary over time; the stock price of the company may be volatile; the company’s dependence on the networking markets served; potential adverse effects of server virtualization technology on the company’s business; potential adverse effects of increased market acceptance of blade servers; the ability to maintain and gain market or industry acceptance of the company’s products; the company’s dependence on a small number of customers; seasonal fluctuations and uneven sales patterns in orders from customers; the company’s ability to compete effectively with other companies; declining average unit sales prices of comparable products; a reduction in sales efforts by current distributors; the company’s dependence on sole source and limited source suppliers; the company’s dependence on relationships with certain third-party subcontractors and contract manufacturers; declines in the market value of the company’s investment securities; the complexity of the company’s products; sales fluctuations arising from customer transitions to new products; changes in the company’s tax provisions or adverse outcomes resulting from examination of its income tax returns; environmental compliance costs; international economic, regulatory, political and other risks; uncertain benefits from strategic business combinations; the ability to attract and retain key personnel; difficulties in transitioning to smaller geometry process technologies; the ability to protect proprietary rights; the ability to satisfactorily resolve any infringement claims; reliance on third party technology; the use of “open source” software in the company’s products; changes in regulations or standards regarding energy use of the company’s products; computer viruses and other tampering with the company’s computer systems; and facilities of the company and its suppliers and customers are located in areas subject to natural disasters.

More detailed information on these and additional factors which could affect the company’s operating and financial results are described in the company’s Forms 10-K, 10-Q and other reports filed, or to be filed, with the Securities and Exchange Commission. The company urges all interested parties to read these reports to gain a better understanding of the business and other risks that the company faces. The forward-looking statements contained in this press release are made only as of the date hereof, and the company does not intend to update or revise these forward-looking statements, whether as a result of new information, future events or otherwise.

QLogic and the QLogic logo are registered trademarks of QLogic Corporation. Other trademarks and registered trademarks are the property of the companies with which they are associated.

QLOGIC CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF INCOME

(unaudited — in thousands, except per share amounts)

	Three Months Ended					Six Months Ended
	September 27,		September 28,			September 27,		September 28,
	2009		2008			2009		2008
Net revenues	$	131,457	$	171,197		$	254,232	$	339,624
Cost of revenues		47,769		55,014			92,238		110,772
Gross profit		83,688		116,183			161,994		228,852
Operating expenses:
Engineering and development		34,238		33,081			68,316		67,448
Sales and marketing		19,991		24,032			39,456		46,977
General and administrative		7,829		9,144			16,143		16,720
Special charges		848		—			848		—
Total operating expenses		62,906		66,257			124,763		131,145
Operating income		20,782		49,926			37,231		97,707
Interest and other income (expense), net		2,336		(2,015	)		5,260		(476	)
Income before income taxes		23,118		47,911			42,491		97,231
Income taxes		6,955		20,756			11,365		38,429
Net income	$	16,163	$	27,155		$	31,126	$	58,802
Net income per share:
Basic	$	0.14	$	0.21		$	0.26	$	0.45
Diluted	$	0.14	$	0.20		$	0.26	$	0.44
Number of shares used in per share calculations:
Basic		117,248		131,421			118,054		131,985
Diluted		117,941		132,810			118,708		133,149

QLOGIC CORPORATION

RECONCILIATION OF GAAP NET INCOME TO
NON-GAAP NET INCOME

(unaudited — in thousands, except per share amounts)

	Three Months Ended						Six Months Ended
	September 27,			September 28,			September 27,			September 28,
	2009			2008			2009			2008
GAAP net income	$	16,163		$	27,155		$	31,126		$	58,802
Items excluded from GAAP net income:
Stock-based compensation		9,006			7,334			18,566			15,139
Amortization of purchased intangible assets		2,616			6,214			4,826			9,606
Acquisition-related stock-based compensation		58			225			117			495
Special charges		848			—			848			—
Gain on sales of previously impaired investment securities		—			—			(605	)		—
Impairment of investment securities		—			5,045			—			7,743
Income taxes		(3,571	)		(773	)		(5,863	)		(4,616	)
Total non-GAAP adjustments		8,957			18,045			17,889			28,367
Non-GAAP net income	$	25,120		$	45,200		$	49,015		$	87,169
Net income per diluted share:
GAAP net income	$	0.14		$	0.20		$	0.26		$	0.44
Adjustments		0.07			0.14			0.15			0.21
Non-GAAP net income	$	0.21		$	0.34		$	0.41		$	0.65

Non-GAAP Financial Measures

The non-GAAP financial measures contained herein are a supplement to the corresponding financial measures prepared in accordance with generally accepted accounting principles (GAAP). The non-GAAP financial measures presented exclude the items summarized in the above table. Management believes that adjustments for these items assist investors in making comparisons of period-to-period operating results and that these items are not indicative of the company’s on-going core operating performance.

The company has presented non-GAAP net income and non-GAAP net income per diluted share, on a basis consistent with its historical presentation, to assist investors in understanding the company’s core net income and core net income per diluted share on an on-going basis. These non-GAAP financial measures may also assist investors in making comparisons of the company’s core net profitability with historical periods and comparisons of the company’s core net profitability with the corresponding results for competitors. Management believes that non-GAAP net income and non-GAAP net income per diluted share are important measures in the evaluation of the company’s profitability. These non-GAAP financial measures exclude the adjustments described in the above table, and thus provide an overall measure of the company’s on-going net profitability and related profitability on a per diluted share basis.

Management uses non-GAAP net income and non-GAAP net income per diluted share in its evaluation of the company’s core after-tax results of operations and trends between fiscal periods and believes that these measures are important components of its internal performance measurement process. In addition, the company prepares and maintains its budgets and forecasts for future periods on a basis consistent with these non-GAAP financial measures. Management believes that providing these non-GAAP

financial measures allows investors to view the company’s financial results in the way that management views the financial results.

The non-GAAP financial measures presented herein have certain limitations in that they do not reflect all of the costs associated with the operations of the company’s business as determined in accordance with GAAP. Therefore, investors should consider non-GAAP financial measures in addition to, and not as a substitute for, or as superior to, measures of financial performance prepared in accordance with GAAP. The non-GAAP financial measures presented by the company may be different from the non-GAAP financial measures used by other companies.

For additional information on the items excluded from the non-GAAP financial measures and why the company believes that these non-GAAP financial measures provide useful supplemental information to investors, the company refers you to the Form 8-K regarding this release filed today with the Securities and Exchange Commission.

A summary of the non-GAAP adjustments presented in the table above by the financial statement line impacted is as follows:

	Three Months Ended						Six Months Ended
	September 27,			September 28,			September 27,			September 28,
(unaudited — in thousands)	2009			2008			2009			2008
Non-GAAP Adjustments:
Cost of revenues:
Stock-based compensation	$	655		$	529		$	1,389		$	1,008
Amortization of purchased intangible assets		1,807			5,375			3,209			7,927
Total cost of revenue adjustments		2,462			5,904			4,598			8,935
Operating expenses:
Engineering and development:
Stock-based compensation		4,530			3,677			9,497			7,852
Amortization of purchased intangible assets		—			31			—			62
Acquisition-related stock-based compensation		58			220			117			484
Sales and marketing:
Stock-based compensation		1,957			1,450			3,601			3,015
Amortization of purchased intangible assets		809			808			1,617			1,617
Acquisition-related stock-based compensation		—			5			—			11
General and administrative:
Stock-based compensation		1,864			1,678			4,079			3,264
Special charges		848			—			848			—
Total operating expense adjustments		10,066			7,869			19,759			16,305
Interest and other income:
Gain on sales of previously impaired investment securities		—			—			(605	)		—
Impairment of investment securities		—			5,045			—			7,743
Total interest and other income adjustments		—			5,045			(605	)		7,743
Total non-GAAP adjustments before income taxes		12,528			18,818			23,752			32,983
Income taxes		(3,571	)		(773	)		(5,863	)		(4,616	)
Total non-GAAP adjustments	$	8,957		$	18,045		$	17,889		$	28,367

QLOGIC CORPORATION

CONDENSED CONSOLIDATED BALANCE SHEETS

(unaudited — in thousands)

	September 27, 2009			March 29, 2009
ASSETS
Current assets:
Cash and cash equivalents	$	153,340		$	203,722
Short-term investment securities		187,021			139,561
Accounts receivable, net		75,227			68,519
Inventories		23,274			40,293
Deferred tax assets		18,935			19,002
Other current assets		15,518			10,854
Total current assets		473,315			481,951
Long-term investment securities		—			34,986
Property and equipment, net		88,828			92,547
Goodwill		119,748			118,859
Purchased intangible assets, net		20,499			19,117
Deferred tax assets		33,407			28,785
Other assets		3,980			4,045
	$	739,777		$	780,290
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	31,460		$	36,874
Accrued compensation		19,565			28,702
Accrued taxes		3,677			13,499
Deferred revenue		8,582			7,470
Other current liabilities		7,524			6,728
Total current liabilities		70,808			93,273
Accrued taxes		41,476			47,116
Deferred revenue		8,513			8,559
Other liabilities		5,173			4,797
Total liabilities		125,970			153,745
Stockholders’ equity:
Common stock		203			202
Additional paid-in capital		736,604			712,064
Retained earnings		1,224,853			1,193,727
Accumulated other comprehensive income		1,147			634
Treasury stock		(1,349,000	)		(1,280,082	)
Total stockholders’ equity		613,807			626,545
	$	739,777		$	780,290

QLOGIC CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(unaudited — in thousands)

	Six Months Ended
	September 27,			September 28,
	2009			2008
Cash flows from operating activities:
Net income	$	31,126		$	58,802
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		15,963			16,456
Stock-based compensation		18,566			15,139
Acquisition-related:
Amortization of purchased intangible assets		4,826			9,606
Stock-based compensation		117			495
Deferred income taxes		3,398			8,276
Net gain on sales of investment securities		(2,082	)		(392	)
Impairment of investment securities		—			7,743
Provision for losses on accounts receivable		54			56
Loss on disposal of property and equipment		54			175
Changes in operating assets and liabilities, net of acquisition:
Accounts receivable		(6,046	)		3,660
Inventories		18,049			(5,767	)
Other assets		(792	)		(2,251	)
Accounts payable		(5,351	)		(13	)
Accrued compensation		(8,997	)		(4,590	)
Accrued taxes		(20,608	)		5,207
Deferred revenue		1,066			1,338
Other liabilities		(747	)		(919	)
Net cash provided by operating activities		48,596			113,021
Cash flows from investing activities:
Purchases of available-for-sale securities		(166,192	)		(115,344	)
Proceeds from sales and maturities of available-for-sale securities		149,441			64,699
Proceeds from disposition of trading securities		8,750			—
Purchases of property and equipment		(12,585	)		(12,841	)
Acquisition of business, net of cash acquired		(14,815	)		—
Net cash used in investing activities		(35,401	)		(63,486	)
Cash flows from financing activities:
Proceeds from issuance of stock under stock plans		7,509			22,030
Minimum tax withholding paid on behalf of employees for restricted stock units		(2,442	)		(1,673	)
Tax effect from issuance of stock under stock plans		(286	)		583
Purchases of treasury stock		(67,424	)		(67,545	)
Payoff of line of credit assumed in acquisition		(934	)		—
Net cash used in financing activities		(63,577	)		(46,605	)
Net increase (decrease) in cash and cash equivalents		(50,382	)		2,930
Cash and cash equivalents at beginning of period		203,722			160,009
Cash and cash equivalents at end of period	$	153,340		$	162,939

QLOGIC CORPORATION

SUPPLEMENTAL FINANCIAL INFORMATION

(unaudited — in thousands)

Net Revenues

A summary of the company’s revenue components is as follows:

	Three Months Ended				Six Months Ended
	September 27,		September 28,		September 27,		September 28,
	2009		2008		2009		2008
Host Products	$	94,026	$	119,667	$	182,355	$	240,317
Network Products		24,491		29,786		49,467		59,689
Silicon Products		9,592		15,660		16,993		31,215
Royalty and Service		3,348		6,084		5,417		8,403
	$	131,457	$	171,197	$	254,232	$	339,624

Geographic Revenues

Revenues by geographic area are presented based upon the country of destination. Net revenues by geographic area are as follows:

	Three Months Ended				Six Months Ended
	September 27,		September 28,		September 27,		September 28,
	2009		2008		2009		2008
United States	$	58,537	$	83,701	$	119,367	$	164,326
Asia-Pacific and Japan		36,470		36,493		62,727		72,425
Europe, Middle East and Africa		27,772		41,987		56,184		83,012
Rest of world		8,678		9,016		15,954		19,861
	$	131,457	$	171,197	$	254,232	$	339,624