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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 EeRqHcDPz1oGjHFu2bLZlw==

<SEC-DOCUMENT>0001262067-10-000039.txt : 20100326
<SEC-HEADER>0001262067-10-000039.hdr.sgml : 20100326
<ACCEPTANCE-DATETIME>20100326192838
ACCESSION NUMBER:		0001262067-10-000039
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100325
FILED AS OF DATE:		20100326
DATE AS OF CHANGE:		20100326

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CASTINO ALFRED
		CENTRAL INDEX KEY:			0001221139

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19807
		FILM NUMBER:		10709037

	MAIL ADDRESS:	
		STREET 1:		C/O AUTODESK INC
		STREET 2:		111 MELNNIS PARKWAY
		CITY:			SAN RAFAEL
		STATE:			CA
		ZIP:			94903

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SYNOPSYS INC
		CENTRAL INDEX KEY:			0000883241
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				561546236
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		700 E MIDDLEFIELD RD
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043-4033
		BUSINESS PHONE:		6509625000

	MAIL ADDRESS:	
		STREET 1:		700 E MIDDLEFIELD RD
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043-4033
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-03-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000883241</issuerCik>
        <issuerName>SYNOPSYS INC</issuerName>
        <issuerTradingSymbol>SNPS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001221139</rptOwnerCik>
            <rptOwnerName>CASTINO ALFRED</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>700 EAST MIDDLEFIELD ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-25</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5543</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20756</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Each Annual Award granted to an Eligible Director in the form of Restricted Stock shall vest and the Corporation's repurchase rights shall lapse in a series of three (3) successive equal annual installments as such individual continues in Board service from the grant date of that Annual Award through the dates immediately preceding each of the first three (3) Annual Meetings following the grant date.</footnote>
        <footnote id="F2">Automatic award under Synopsys 2005 Non-Employee Directors Equity Incentive Plan</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Stephen Buckhout pursuant to POA  For: Alfred Castino</signatureName>
        <signatureDate>2010-03-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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