-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 A7sl9dCxO9qDUerMcLr9c7sRmkLyVaVf3AiZbiyFNUuvAEgsN/RrPXIZU+Fh+4XS
 YYzs9I/qn2tbACnyxuMRwg==

<SEC-DOCUMENT>0001179110-03-005700.txt : 20030814
<SEC-HEADER>0001179110-03-005700.hdr.sgml : 20030814
<ACCEPTANCE-DATETIME>20030814195724
ACCESSION NUMBER:		0001179110-03-005700
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030814
FILED AS OF DATE:		20030814

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LONG ROBERT LIVINGSTON
		CENTRAL INDEX KEY:			0001220668

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15086
		FILM NUMBER:		03849303

	BUSINESS ADDRESS:	
		STREET 1:		C/O SUN MICROSYSTEMS INC
		STREET 2:		4120 NETWORK CIRCLE M/S SCA12-202
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
		BUSINESS PHONE:		4082763902

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SUN MICROSYSTEMS INC
		CENTRAL INDEX KEY:			0000709519
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC COMPUTERS [3571]
		IRS NUMBER:				942805249
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		4150 NETWORK CIRCLE
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
		BUSINESS PHONE:		6509601300

	MAIL ADDRESS:	
		STREET 1:		4150 NETWORK CIRCLE
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 5 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>5</documentType>
<periodOfReport>2003-08-14</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000709519</issuerCik>
        <issuerName>SUN MICROSYSTEMS INC</issuerName>
        <issuerTradingSymbol>sunw</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220668</rptOwnerCik>
            <rptOwnerName>LONG ROBERT LIVINGSTON</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4150 NETWORK CIRCLE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle></officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-04-08</value>
</transactionDate>
<transactionCoding><transactionFormType>5</transactionFormType>
<transactionCode>G</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>70000</value>
</transactionShares>
<transactionPricePerShare><footnoteId id="F1"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>53127</value>
<footnoteId id="F2"></footnoteId>
<footnoteId id="F3"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-01-24</value>
</transactionDate>
<transactionCoding><transactionFormType>5</transactionFormType>
<transactionCode>G</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>24184</value>
</transactionShares>
<transactionPricePerShare><footnoteId id="F1"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By The Robert L. Long Irrevocable GRAT Trust No. 2</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-01-24</value>
</transactionDate>
<transactionCoding><transactionFormType>5</transactionFormType>
<transactionCode>G</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>6579</value>
</transactionShares>
<transactionPricePerShare><footnoteId id="F1"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>43421</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By The Phyllis C Long GRAT No. 1</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>1988-08-08</value>
<footnoteId id="F4"></footnoteId>
</transactionDate>
<transactionCoding><transactionFormType>5</transactionFormType>
<transactionCode>J</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
<footnoteId id="F5"></footnoteId>
</transactionCoding>
<transactionAmounts><transactionShares><value>0</value>
<footnoteId id="F5"></footnoteId>
</transactionShares>
<transactionPricePerShare><value>0</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>72500</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By LLP</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes><footnote id="F1">Price is not applicable for gift.</footnote>
<footnote id="F2">Reflects the transfer of 24,184 shares from The Robert L. Long Irrevocable GRAT Trust No. 2 to Robert L. Long on January 24, 2003.</footnote>
<footnote id="F3">Reflects the transfer of 6,579 shares from The Phyllis C. Long Irrevocable GRAT Trust No. 1 to Robert L. Long on January 24, 2003.</footnote>
<footnote id="F4">In the Section 16 Electronic Reporting Frequently Asked Questions released by the SEC on May 1, 2003, the SEC has designated "08/08/1988" as a "dummy date" until the electronic system is modified.  This line reports end of period indirect holdings for this reporting person, and 08/08/1988 is not a transaction date related to these securities.</footnote>
<footnote id="F5">There has been no transaction in the indirect holdings for this reporting person.</footnote>
</footnotes>
<ownerSignature><signatureName>Robert L. Long</signatureName>
<signatureDate>2003-08-14</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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