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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001262067-10-000103.txt : 20101210
<SEC-HEADER>0001262067-10-000103.hdr.sgml : 20101210
<ACCEPTANCE-DATETIME>20101210164412
ACCESSION NUMBER:		0001262067-10-000103
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101208
FILED AS OF DATE:		20101210
DATE AS OF CHANGE:		20101210

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHAN CHI-FOON
		CENTRAL INDEX KEY:			0001249834

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19807
		FILM NUMBER:		101245443

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
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        <issuerName>SYNOPSYS INC</issuerName>
        <issuerTradingSymbol>SNPS</issuerTradingSymbol>
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    <derivativeTable>
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            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
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                <value>26.56</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-12-09</value>
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    <footnotes>
        <footnote id="F1">These shares were retained by the Company in order to meet the tax withholding obligations of the award holder in connection with the vesting of an installment of the performance restricted stock unit award. The Compensation Committee approved the disposition of shares by the award holder and the amount retained by the Company was not in excess of the amount of the tax liability.</footnote>
        <footnote id="F2">These shares were retained by the Company in order to meet the tax withholding obligations of the award holder in connection with the vesting of an installment of the  restricted stock unit award. The Compensation Committee approved the disposition of shares by the award holder and the amount retained by the Company was not in excess of the amount of the tax liability.</footnote>
        <footnote id="F3">Upon vesting, each restricted stock unit was converted into an equivalent number of shares of common stock.</footnote>
        <footnote id="F4">Grant to reporting person to buy shares of common stock under the Synopsys, Inc 2006 Employee Equity Incentive Plan</footnote>
        <footnote id="F5">Option vests in 16 equal quarterly installments beginning on the date shown.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Stephen Buckhout pursuant to POA  For: Chi-Foon Chan</signatureName>
        <signatureDate>2010-12-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</DOCUMENT>
</SEC-DOCUMENT>
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