-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 SrFHjYdiADIMzmlHcUsZ0G1z9dYfJjB83s5/054Q6La7TT1J/UoFNhGHRCpalXMB
 pFgvqJL1JDzqncvTE5LwJQ==

<SEC-DOCUMENT>0001179110-06-014740.txt : 20060706
<SEC-HEADER>0001179110-06-014740.hdr.sgml : 20060706
<ACCEPTANCE-DATETIME>20060706141025
ACCESSION NUMBER:		0001179110-06-014740
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060703
FILED AS OF DATE:		20060706
DATE AS OF CHANGE:		20060706

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GILEAD SCIENCES INC
		CENTRAL INDEX KEY:			0000882095
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				943047598
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		333 LAKESIDE DR
		CITY:			FOSTER CITY
		STATE:			CA
		ZIP:			94404
		BUSINESS PHONE:		6505743000

	MAIL ADDRESS:	
		STREET 1:		333 LAKESIDE DR
		CITY:			FOSTER CITY
		STATE:			CA
		ZIP:			94404

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Cogan John Francis
		CENTRAL INDEX KEY:			0001319872

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19731
		FILM NUMBER:		06947452

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(408) 436-8577

	MAIL ADDRESS:	
		STREET 1:		2010 NORTH FIRST STREET, SUITE 310
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-07-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000882095</issuerCik>
        <issuerName>GILEAD SCIENCES INC</issuerName>
        <issuerTradingSymbol>GILD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001319872</rptOwnerCik>
            <rptOwnerName>Cogan John Francis</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>HOOVER INSTITUTION</rptOwnerStreet1>
            <rptOwnerStreet2>434 GALVEZ MALL</rptOwnerStreet2>
            <rptOwnerCity>STANFORD</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94305-6010</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>59.26</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-07-03</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2006-07-03</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1012.49</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>59.26</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1012.49</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1012.49</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of phantom stock are fully vested and, at the election of the reporting person, become payable in common stock when the reporting person reaches the age of 65.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/John Milligan, by Power of Attorney fpr John F. Cogan</signatureName>
        <signatureDate>2006-07-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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