Exhibit 99.1

For Immediate Release

GILEAD SCIENCES ANNOUNCES THIRD QUARTER 2010 FINANCIAL RESULTS

- Total Revenues of $1.94 Billion, Up 8 Percent over Third Quarter 2009 -

- Record Product Sales of $1.87 Billion, Up 13 Percent over Third Quarter 2009 -

- Third Quarter Non-GAAP EPS of $0.90 per Share, Up 15 Percent over Third Quarter 2009 -

Foster City, CA, October 19, 2010 - Gilead Sciences, Inc. (Nasdaq: GILD) announced today its results of operations for the quarter ended September 30, 2010. Total revenues for the third quarter of 2010 were $1.94 billion, up 8 percent compared to total revenues of $1.80 billion for the third quarter of 2009. Net income for the third quarter of 2010 was $704.9 million, or $0.83 per diluted share, compared to net income for the third quarter of 2009 of $673.0 million, or $0.72 per diluted share. Non-GAAP net income for the third quarter of 2010, which excludes after-tax acquisition-related expenses, restructuring expenses and stock-based compensation expenses, was $759.7 million, or $0.90 per diluted share. Non-GAAP net income for the third quarter of 2009, which excludes after-tax acquisition-related expenses, restructuring expenses and stock-based compensation expenses, was $730.3 million, or $0.78 per diluted share.

Product Sales

Product sales increased 13 percent to $1.87 billion for the third quarter of 2010, compared to $1.65 billion in the third quarter of 2009.

Antiviral Franchise

Antiviral product sales increased 12 percent to $1.65 billion in the third quarter of 2010, up from $1.47 billion for the same quarter of 2009.

Sales of Atripla^® (efavirenz 600 mg/ emtricitabine 200 mg/ tenofovir disoproxil fumarate 300 mg) for the treatment of HIV infection increased 23 percent to $742.7 million for the third quarter of 2010, up from $605.3 million in the third quarter of 2009, driven primarily by sales volume growth in the United States and Europe.

Sales of Truvada^® (emtricitabine/tenofovir disoproxil fumarate) for the treatment of HIV infection increased 8 percent to $668.7 million for the third quarter of 2010, up from $620.6 million in the third quarter of 2009, driven primarily by sales volume growth in the United States and Europe.

Sales of Viread^® (tenofovir disoproxil fumarate) for the treatment of HIV infection and chronic hepatitis B increased 9 percent to $184.3 million for the third quarter of 2010, up from $169.7 million in the third quarter of 2009, driven primarily by sales volume growth in the United States, Europe and Latin America.

- more -

Letairis

Sales of Letairis^® (ambrisentan) for the treatment of pulmonary arterial hypertension increased 26 percent to $60.4 million for the third quarter of 2010, up from $48.1 million for the third quarter of 2009, driven primarily by sales volume growth in the United States.

Ranexa

Sales of Ranexa^® (ranolazine) for the treatment of chronic angina increased 23 percent to $60.3 million for the third quarter of 2010, up from $49.0 million for the third quarter of 2009, driven primarily by sales volume growth in the United States.

Other Products

Sales of other products were $149.1 million for the third quarter of 2010 compared to $156.3 million for the third quarter of 2009 and included AmBisome^® (amphotericin B liposome for injection) for the treatment of severe fungal infections, Hepsera^® (adefovir dipivoxil) for the treatment of chronic hepatitis B, Emtriva^® (emtricitabine) for the treatment of HIV infection, and Cayston^® (aztreonam for inhalation solution) for the improvement of respiratory symptoms in cystic fibrosis patients with Pseudomonas aeruginosa (P. aeruginosa). Sales of Cayston were $14.7 million for the third quarter of 2010.

Royalty, Contract and Other Revenues

Royalty, contract and other revenues resulting primarily from collaborations with corporate partners were $72.1 million in the third quarter of 2010, down from $152.4 million in the third quarter of 2009. This decrease was due primarily to lower Tamiflu^® (oseltamivir phosphate) royalties from F. Hoffmann-La Roche Ltd of $34.5 million in the third quarter of 2010, compared to Tamiflu royalties of $113.5 million in the third quarter of 2009.

Research and Development

Research and development (R&D) expenses in the third quarter of 2010 were $230.4 million, compared to $269.9 million for the third quarter of 2009. Non-GAAP R&D expenses for the third quarter of 2010, which exclude restructuring and stock-based compensation expenses, were $203.2 million, compared to $242.2 million for the third quarter of 2009. The decrease in non-GAAP R&D expenses was due primarily to lower R&D expense reimbursement related to Gilead’s collaboration with Tibotec Pharmaceuticals (Tibotec).

Selling, General and Administrative

Selling, general and administrative (SG&A) expenses in the third quarter of 2010 were $250.6 million, compared to $227.4 million for the third quarter of 2009. Non-GAAP SG&A expenses for the third quarter of 2010, which exclude acquisition-related, restructuring and stock-based compensation expenses, were $220.6 million, compared to $200.3 million for the third quarter in 2009. The increase in non-GAAP SG&A expenses was driven primarily by higher headcount and expenses to support Gilead’s expanding commercial activities.

Net Foreign Currency Exchange Impact

The net foreign currency exchange impact on third quarter 2010 revenues and pre-tax earnings, which includes revenues and expenses generated from outside the United States, was an unfavorable $44.2 million and $37.4 million, respectively, compared to the third quarter of 2009, and an unfavorable $7.0 million and $1.7 million, respectively, compared to the second quarter of 2010.

Cash, Cash Equivalents and Marketable Securities

As of September 30, 2010, Gilead had cash, cash equivalents and marketable securities of $5.05 billion compared to $3.90 billion as of December 31, 2009. Gilead generated $2.11 billion of operating cash flow for the first nine months of 2010 including $739.5 million in the third quarter of 2010.

- more -

Corporate Highlights

Under the company’s previously announced $5.0 billion stock repurchase program authorized by its Board of Directors in May 2010, Gilead has repurchased approximately $2.41 billion in common stock through September 30, 2010. In conjunction with the company’s announcement of its convertible debt offering on July 26, 2010, Gilead has since acquired approximately $1.18 billion of shares repurchased at an average price of $33.84 per share. Total purchase activity was $1.55 billion in common stock for the third quarter of 2010. Total purchase activity for the year to date was $3.41 billion in common stock, representing 93.6 million repurchased shares or approximately 10% of Gilead’s total common shares outstanding at December 31, 2009.

Product and Pipeline Update

Antiviral Franchise

In September, Gilead announced that it had submitted a Marketing Authorization Application to the European Medicines Agency for marketing approval of the fixed-dose combination of Truvada and Tibotec’s investigational non-nucleoside reverse transcriptase inhibitor TMC278 (rilpivirine) for the treatment of HIV-1 infection in adults.

Also in September, Gilead released positive 48-week results from two of its ongoing Phase II clinical studies in HIV-infected patients. The first were from the study of its investigational fixed-dose, single-tablet “Quad” regimen of elvitegravir, cobicistat and Truvada versus Atripla. The second were from the study of cobicistat-boosted atazanavir plus Truvada compared to ritonavir-boosted atazanavir plus Truvada. Results from both studies were presented at the 50th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy in Boston.

Conference Call

At 5:00 p.m. Eastern Time today, Gilead’s management will host a conference call and a simultaneous webcast to discuss results from its third quarter 2010 as well as provide a general business update. To access the webcast live via the internet, please connect to the company’s website at www.gilead.com 15 minutes prior to the conference call to ensure adequate time for any software download that may be needed to hear the webcast. Alternatively, please call 1-866-770-7051 (U.S.) or 1-617-213-8064 (international) and dial the participant passcode 16880218 to access the call.

A replay of the webcast will be archived on the company’s website for one year, and a phone replay will be available approximately two hours following the call through October 22, 2010. To access the phone replay, please call 1-888-286-8010 (U.S.) or 1-617-801-6888 (international) and dial the participant passcode 60311851.

About Gilead

Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. Gilead’s mission is to advance the care of patients suffering from life-threatening diseases worldwide. Headquartered in Foster City, California, Gilead has operations in North America, Europe and Australia.

Non-GAAP Financial Information

Gilead has presented certain financial information in accordance with GAAP and also on a non-GAAP basis for the three and nine months ended September 30, 2010 and 2009. Management believes this non-GAAP information is useful for investors, taken in conjunction with Gilead’s GAAP financial statements, because management uses such information internally for its operating, budgeting and financial planning purposes. Non-GAAP information is not prepared under a comprehensive set of accounting rules and should only be used to supplement an understanding of Gilead’s operating results as reported under U.S. GAAP. A reconciliation between GAAP and non-GAAP financial information is provided in the table on page 6.

- more -

Forward-looking Statements

Statements included in this press release that are not historical in nature are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Gilead cautions readers that forward-looking statements are subject to certain risks and uncertainties that could cause actual results to differ materially. These risks and uncertainties include: Gilead’s ability to sustain growth in revenues for its antiviral, cardiovascular and respiratory franchises; unpredictable variability of Tamiflu royalties and the strong relationship between this royalty revenue and global pandemic planning and supply; Gilead’s ability to submit NDAs for new product candidates, including the fixed-dose combination of Truvada and TMC278, in the timelines currently anticipated; Gilead’s ability to receive regulatory approvals in a timely manner or at all, for new and current products, including its investigational fixed-dose single-tablet “Quad” regimen of elvitegravir, cobicistat (formerly GS 9350) and Truvada and the fixed-dose combination of Truvada and TMC278, both for the treatment of HIV infection; Gilead’s ability to successfully commercialize its products, including Cayston as a treatment for the improvement of respiratory symptoms in cystic fibrosis patients with P. aeruginosa; Gilead’s ability to successfully develop its respiratory and cardiovascular franchises; safety and efficacy data from clinical studies may not warrant further development of Gilead’s product candidates, including the Quad and the fixed-dose combination of Truvada and TMC278; initiating and completing clinical trials may take longer or cost more than expected, including in the clinical studies evaluating the Quad for the treatment of HIV infection; fluctuations in the foreign exchange rate of the U.S. dollar that may reduce or eliminate the favorable foreign currency exchange impact on Gilead’s future revenues and pre-tax earnings; Gilead’s ability to consummate the $5.0 billion share repurchase program due to changes in its stock price, corporate or other market conditions; risks and uncertainties related to Gilead’s ability to successfully advance CGI Pharmaceuticals, Inc.’s pipeline programs; whether the FDA or other international regulatory authorities will agree that steps taken or to be taken by Gilead to correct matters described in the Warning Letter received from the FDA on September 24, 2010, with respect to Gilead’s manufacturing and distribution center in San Dimas, California, are adequate; Gilead’s ability to resolve any continuing concerns that may be expressed by the FDA or other international regulatory authorities in a timely manner and whether the FDA or other international regulatory authorities decide to take further corrective or disciplinary actions against Gilead, including, without limitation, withholding permission to export AmBisome to certain countries outside the United States and Europe; and other risks identified from time to time in Gilead’s reports filed with the U.S. Securities and Exchange Commission. In addition, Gilead makes estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosures. Gilead bases its estimates on historical experience and on various other market-specific and other relevant assumptions that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ significantly from these estimates. You are urged to consider statements that include the words “may,” “will,” “would,” “could,” “should,” “might,” “believes,” “estimates,” “projects,” “potential,” “expects,” “plans,” “anticipates,” “intends,” “continues,” “forecast,” “designed,” “goal,” or the negative of those words or other comparable words to be uncertain and forward-looking. Gilead directs readers to its Quarterly Reports on Form 10-Q for the first and second quarters and other publicly filed disclosure documents filed with the Securities and Exchange Commission and subsequent press releases. Gilead claims the protection of the Safe Harbor contained in the Private Securities Litigation Reform Act of 1995 for forward-looking statements. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation to update any such forward-looking statements.

# # #

Truvada, Viread, Hepsera, Emtriva, AmBisome, Letairis, Cayston and Ranexa are

registered trademarks of Gilead Sciences, Inc.

Atripla is a registered trademark of Bristol-Myers Squibb & Gilead Sciences, LLC.

Tamiflu is a registered trademark of F. Hoffmann-La Roche Ltd.

For more information on Gilead Sciences, Inc., please visit www.gilead.com or

call the Gilead Public Affairs Department at 1-800-GILEAD-5 (1-800-445-3235).

GILEAD SCIENCES, INC.

CONDENSED CONSOLIDATED STATEMENTS OF INCOME

(unaudited)

(in thousands, except per share amounts)

GILEAD SCIENCES, INC.

RECONCILIATION OF GAAP TO NON-GAAP FINANCIAL INFORMATION

(unaudited)

(in thousands, except percentages and per share amounts)

Note:

GILEAD SCIENCES, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(in thousands)

Notes:

GILEAD SCIENCES, INC.

PRODUCT SALES SUMMARY

(unaudited)

(in thousands)