<SEC-DOCUMENT>0001127602-18-028011.txt : 20180919
<SEC-HEADER>0001127602-18-028011.hdr.sgml : 20180919
<ACCEPTANCE-DATETIME>20180919142902
ACCESSION NUMBER:		0001127602-18-028011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180815
FILED AS OF DATE:		20180919
DATE AS OF CHANGE:		20180919

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Pletcher Brett A
		CENTRAL INDEX KEY:			0001739307

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19731
		FILM NUMBER:		181077591

	MAIL ADDRESS:	
		STREET 1:		333 LAKESIDE DRIVE
		CITY:			FOSTER CITY
		STATE:			X1
		ZIP:			94404

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-08-15</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001739307</rptOwnerCik>
            <rptOwnerName>Pletcher Brett A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>333 LAKESIDE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FOSTER CITY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94404</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>EVP, Gen Counsel &amp; Corp Sec</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-08-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>94</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>63.614</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20706</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Gilead Sciences, Inc. Employee Stock Purchase Plan (&quot;ESPP&quot;) for the ESPP purchase period of February 16, 2018 through August, 15 2018. This transaction is exempt under Rule 16b-3(c).</footnote>
        <footnote id="F2">In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on August 15, 2018.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Marissa Song by Power of Attorney for Brett A Pletcher</signatureName>
        <signatureDate>2018-09-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
