<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-09-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000723458</issuerCik>
        <issuerName>STATE BANCORP INC</issuerName>
        <issuerTradingSymbol>STBC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001223539</rptOwnerCik>
            <rptOwnerName>BRAUN FREDERICK C III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2 JERICHO PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2>2ND FLOOR, WING C</rptOwnerStreet2>
            <rptOwnerCity>JERICHO</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11753</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>State Bancorp, Inc. Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-09-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34646.486</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>State Bancorp, Inc. Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17619.4779</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through ESOP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>22.63</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-02-14</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-02-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6000</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19.16</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-02-23</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-02-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6300</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6300</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.61</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-02-24</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-02-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6614</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6614</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>12.45</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-02-26</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2012-02-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7778</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7778</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.28</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2001-02-27</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2011-02-27</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>11668</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11668</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2000-02-29</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-02-28</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3936</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3936</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>ISO</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.33</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1999-01-25</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2009-01-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>STB Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4172</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4172</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Total includes 7,500 shares of restricted stock granted to Mr. Braun as part of his 2007 incentive compensation package.  Shares vest over a five year period; one-third to vest after the expiration of year three; one-third to vest after the expiration of year four; and the remainder to vest after the expiration of year five.</footnote>
        <footnote id="F2">These options are subject to a five year schedule (0% the first year and 25% each of the following years).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Frederick C. Braun III</signatureName>
        <signatureDate>2008-09-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
