Exhibit 99.1

PRESS RELEASE

INVESTOR CONTACT:

Lisa L. Ewbank

Synopsys, Inc.

650-584-1901

EDITORIAL CONTACT:

Yvette Huygen

Synopsys, Inc.

650-584-4547

yvetteh@synopsys.com

Synopsys Posts Financial Results for Second Quarter Fiscal Year 2011

MOUNTAIN VIEW, Calif. – May 18, 2011 – Synopsys, Inc. (Nasdaq: SNPS), a world leader in software and IP for semiconductor design, verification and manufacturing, today reported results for its second quarter of fiscal year 2011.

For the second quarter of fiscal year 2011, Synopsys reported revenue of $393.7 million, compared to $338.1 million for the second quarter of fiscal 2010, an increase of 16.4%.

“Synopsys delivered strong second quarter results as we continue to execute well,” said Aart de Geus, chairman and CEO of Synopsys. “Our technology pipeline, delivery and customer adoption remain strong, and we continue to see momentum in our IP and Systems products.”

GAAP Results

On a generally accepted accounting principles (GAAP) basis, net income for the second quarter of fiscal 2011 was $81.1 million, or $0.53 per share, compared to $39.5 million, or $0.26 per share, for the second quarter of fiscal 2010. Net income for the second quarter of fiscal 2011 includes a one-time $32.8 million, or $0.21 per share, tax benefit associated with a settlement with the IRS for audits for fiscal years 2006 through 2009.

Non-GAAP Results

On a non-GAAP basis, net income for the second quarter of fiscal 2011 was $68.5 million, or $0.45 per share, compared to non-GAAP net income of $61.9 million, or $0.41 per share, for the second quarter of fiscal 2010. Reconciliation between GAAP and non-GAAP results is provided at the end of this press release.

Financial Targets

Synopsys also provided its financial targets for the third quarter and full fiscal year 2011. These targets do not include future acquisition-related costs that may be incurred in fiscal 2011. These targets constitute forward-looking information and are based on current expectations. For a discussion of factors that could cause actual results to differ materially from these targets, see “Forward-Looking Statements” below.

Third Quarter of Fiscal Year 2011 Targets:

Full Fiscal Year 2011 Targets:

GAAP Reconciliation

Synopsys continues to provide all information required in accordance with GAAP, but believes evaluating its ongoing operating results may not be as useful if an investor is limited to reviewing only GAAP financial measures. Accordingly, Synopsys presents non-GAAP financial measures in reporting its financial results to provide investors with an additional tool to evaluate Synopsys’ operating results in a manner that focuses on what Synopsys believes to be its ongoing business operations and what Synopsys uses to evaluate its ongoing operations and for internal planning and forecasting purposes. Synopsys’ management does not itself, nor does it suggest that investors should, consider such non-GAAP financial measures in isolation from, or as a substitute for, financial information prepared in accordance with GAAP. Synopsys’ management believes it is useful for itself and investors to review, as applicable, both GAAP information that includes: (i) the amortization of acquired intangible assets, (ii) the impact of stock compensation, (iii) acquisition-related costs, (iv) other significant items, including the effect of tax benefits from settlements with the Internal Revenue Service, and (v) the income tax effect of non-GAAP pre-tax adjustments from the provision for income taxes; and the non-GAAP measures that exclude such information in order to assess the performance of Synopsys’ business and for planning and forecasting in subsequent periods. Whenever Synopsys uses a non-GAAP financial measure, it provides a reconciliation of the non-GAAP financial measure to the most closely applicable GAAP financial measure. Investors are encouraged to review the related GAAP financial measures and the reconciliation of these non-GAAP financial measures to their most directly comparable GAAP financial measure as detailed below.

Reconciliation of Second Quarter Fiscal Year 2011 Results

The following tables reconcile the specific items excluded from GAAP in the calculation of non-GAAP net income and earnings per share for the periods indicated below.

GAAP to Non-GAAP Reconciliation of Second Quarter Fiscal Year 2011 Results

(unaudited and in thousands, except per share amounts)

Reconciliation of Target Non-GAAP Operating Results

The following tables reconcile the specific items excluded from GAAP in the calculation of target non-GAAP operating results for the periods indicated below.

GAAP to Non-GAAP Reconciliation of Third Quarter Fiscal Year 2011 Targets

(in thousands, except per share amounts)

Earnings Call Open to Investors

Synopsys will hold a conference call for financial analysts and investors today at 2:00 p.m., Pacific Time. A live webcast of the call will be available at Synopsys’ corporate website at www.synopsys.com. A recording of the call will be available by dialing +1-800-475-6701 (+1-320-365-3844 for international callers), access code 203338, beginning at 4:00 p.m. Pacific Time today. A webcast replay will also be available on the website from approximately 5:30 p.m. Pacific Time today through the time Synopsys announces its results for the third quarter fiscal 2011 in August 2011. Synopsys will post copies of the prepared remarks of Aart de Geus, chairman and chief executive officer, and Brian Beattie, chief financial officer, on its website following the call. In addition, Synopsys makes additional financial information available in a financial supplement also posted on the corporate website.

Effectiveness of Information

The targets included in this release, the statements made during the earnings conference call and the information contained in the financial supplement (available in the Investor Relations section of Synopsys’ website at www.synopsys.com) represent Synopsys’ expectations and beliefs as of the date of this release only. Although this press release, copies of the prepared remarks of the chief executive officer and chief financial officer made during the call and the financial supplement will remain available on Synopsys’ website through the date of the third quarter fiscal year 2011 earnings call in August 2011, their continued availability through such date does not mean that Synopsys is reaffirming or confirming their continued validity. Synopsys does not currently intend to report on its progress during the third quarter of fiscal 2011 or comment to analysts or investors on, or otherwise update, the targets given in this earnings release.

Availability of Final Financial Statements

Synopsys will include final financial statements for the second quarter fiscal 2011 in its quarterly report on Form 10-Q to be filed by June 9, 2011.

About Synopsys

Synopsys, Inc. (Nasdaq: SNPS) is a world leader in electronic design automation (EDA), supplying the global electronics market with the software, intellectual property (IP) and services used in semiconductor design, verification and manufacturing. Synopsys’ comprehensive, integrated portfolio

of implementation, verification, IP, manufacturing and field-programmable gate array (FPGA) solutions helps address the key challenges designers and manufacturers face today, such as power and yield management, system-to-silicon verification and time-to-results. These technology-leading solutions help give Synopsys customers a competitive edge in bringing the best products to market quickly while reducing costs and schedule risk. Synopsys is headquartered in Mountain View, California, and has approximately 70 offices located throughout North America, Europe, Japan, Asia and India. Visit Synopsys online at http://www.synopsys.com/.

Forward-Looking Statements

The statements made in this press release regarding projected financial results in the sections entitled “Financial Targets” and “Reconciliation of Target Non-GAAP Operating Results,” financial objectives, and certain statements made in the earnings conference call are forward-looking statements within the meaning of the safe harbor provisions of Section 21E of the Securities Exchange Act of 1934. Actual results could differ materially from those described by these statements due to a number of uncertainties, including, but not limited to:

In addition, Synopsys’ actual expenses, earnings per share and tax rate on a GAAP and non-GAAP basis for the fiscal quarter ending July 31, 2011 and actual expenses, earnings per share, tax rate, cash flow from operations and other projections on a GAAP and non-GAAP basis for fiscal year 2011 could differ materially from the targets stated under “Financial Targets” above for a number of reasons, including, but not limited to, (i) a determination by Synopsys that any portion of its goodwill or intangible assets have become impaired, (ii) application of the actual consolidated GAAP and non-GAAP tax rates for such periods, or judgment by management, based upon the status of pending audits and settlements, to increase or decrease an income tax asset or liability, (iii) integration and other acquisition-related costs including amortization of intangible assets and costs formerly capitalized but now expensed due to new accounting guidance related to business combinations, as well as changes in the fair value of contingent consideration related to prior acquisitions, (iv) changes in the anticipated amount of employee stock compensation expense recognized on Synopsys’ financial statements, (v) actual change in the fair value of Synopsys’ non-qualified deferred compensation plan obligations, (vi) increases or decreases to estimated capital expenditures, (vii) changes driven by new accounting rules, regulations, interpretations or guidance, (viii) general economic conditions, and (ix) other risks as detailed in Synopsys’ SEC filings, including those described in the “Risk Factors” section in the latest Quarterly Report on Form 10-Q for the first fiscal quarter ended January 31, 2011. Furthermore, Synopsys’ actual tax rates applied to income for the third quarter and fiscal year 2011 could differ from the targets given in this press release as a result of a number of factors, including the actual geographic mix of revenue during the quarter and year, and actions by the government. Finally, Synopsys’ targets for outstanding shares in the third quarter and fiscal year 2011 could differ from the targets given in this press release as a result of higher than expected employee stock plan issuances or stock option exercises, acquisitions and the extent of Synopsys’ stock repurchase activity.

Synopsys is under no obligation (and expressly disclaims any obligation) to update or alter any of the forward-looking statements made in this earnings release, the conference call or the financial supplement whether as a result of new information, future events or otherwise, unless otherwise required by law.

###

Synopsys is a registered trademark of Synopsys, Inc. Any other trademarks mentioned in this release are the property of their respective owners.

SYNOPSYS, INC.

Unaudited Consolidated Statements of Operations (1)

(in thousands, except per share amounts)

SYNOPSYS, INC.

Unaudited Consolidated Balance Sheets (1)

(in thousands, except par value amounts)

SYNOPSYS, INC.

Unaudited Consolidated Statements of Cash Flows (1)

(in thousands)