<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-11-18</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000039648</issuerCik>
        <issuerName>G&amp;K SERVICES INC</issuerName>
        <issuerTradingSymbol>GKSR</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186366</rptOwnerCik>
            <rptOwnerName>MOBERLY THOMAS R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O G&amp;K SERVICES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>5995 OPUS PARKWAY, SUITE 500</rptOwnerStreet2>
            <rptOwnerCity>MINNETONKA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55343</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Chief Executive Officer</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<transactionDate><value>2003-11-18</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>30</value>
</transactionShares>
<transactionPricePerShare><value>35.6</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>50631</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<transactionDate><value>2003-11-19</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>5796</value>
</transactionShares>
<transactionPricePerShare><value>35</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>44835</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<transactionDate><value>2003-11-19</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>1075</value>
</transactionShares>
<transactionPricePerShare><value>35.07</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>43760</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<transactionDate><value>2003-11-19</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>100</value>
</transactionShares>
<transactionPricePerShare><value>35.08</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>43660</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<transactionDate><value>2003-11-19</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>100</value>
</transactionShares>
<transactionPricePerShare><value>35.06</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>43560</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<transactionDate><value>2003-11-19</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>2417</value>
</transactionShares>
<transactionPricePerShare><value>35.05</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>41143</value>
<footnoteId id="F1"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeHolding><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>11400</value>
<footnoteId id="F2"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeHolding>
<nonDerivativeHolding><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>1000</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By spouse</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
<nonDerivativeHolding><securityTitle><value>Class A Common Stock</value>
</securityTitle>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>726</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>I</value>
</directOrIndirectOwnership>
<natureOfOwnership><value>By reporting person as custodian for children</value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
</nonDerivativeTable>
<derivativeTable><derivativeHolding><securityTitle><value>Employee Stock Option</value>
<footnoteId id="F3"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>41.875</value>
</conversionOrExercisePrice>
<exerciseDate><footnoteId id="F4"></footnoteId>
</exerciseDate>
<expirationDate><value>2008-01-02</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>2160</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>2160</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding><securityTitle><value>Employee Stock Option</value>
<footnoteId id="F3"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>46</value>
</conversionOrExercisePrice>
<exerciseDate><value>2001-09-01</value>
</exerciseDate>
<expirationDate><value>2008-09-01</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>2880</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>2880</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding><securityTitle><value>Employee Stock Option</value>
<footnoteId id="F3"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>41.5625</value>
</conversionOrExercisePrice>
<exerciseDate><value>2002-09-01</value>
</exerciseDate>
<expirationDate><value>2009-09-01</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>4391</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>4391</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding><securityTitle><value>Employee Stock Option</value>
<footnoteId id="F3"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>27.95</value>
</conversionOrExercisePrice>
<exerciseDate><value>2004-09-01</value>
</exerciseDate>
<expirationDate><value>2011-09-01</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>8050</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>8050</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding><securityTitle><value>Employee Stock Option</value>
<footnoteId id="F3"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>35.69</value>
</conversionOrExercisePrice>
<exerciseDate><footnoteId id="F5"></footnoteId>
</exerciseDate>
<expirationDate><value>2013-01-02</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>21000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>21000</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding><securityTitle><value>Employee Stock Option</value>
<footnoteId id="F3"></footnoteId>
</securityTitle>
<conversionOrExercisePrice><value>32.57</value>
</conversionOrExercisePrice>
<exerciseDate><footnoteId id="F6"></footnoteId>
</exerciseDate>
<expirationDate><value>2013-08-25</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>23505</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>23505</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeHolding>
</derivativeTable>
<footnotes><footnote id="F1">Includes purchases through the Employee Stock Purchase Plan.  Also includes restricted stock grant pursuant to the 1998 Stock Option and Compensation Plan.</footnote>
<footnote id="F2">Owned jointly with spouse.</footnote>
<footnote id="F3">Pursuant to Rule 16b-3 (right to buy)</footnote>
<footnote id="F4">Option vests as follows:  309 shares each on 1/2/99, 1/2/00, 1/2/01 and 1/2/02.  308 shares each on 1/2/03, 1/2/04 and 1/2/05.</footnote>
<footnote id="F5">7000 shares each vest on 1/2/04, 1/2/05 and 1/2/06.</footnote>
<footnote id="F6">7,835 shares each vest on 8/25/04, 8/25/05 and 8/25/06.</footnote>
</footnotes>
<ownerSignature><signatureName>/s/ Thomas R. Moberly</signatureName>
<signatureDate>2003-11-20</signatureDate>
</ownerSignature>
</ownershipDocument>

