<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="../4_X02.xsl"?><ownershipDocument>    <schemaVersion>X0303</schemaVersion>    <documentType>4</documentType>    <periodOfReport>2010-09-02</periodOfReport>    <notSubjectToSection16>0</notSubjectToSection16>    <issuer>        <issuerCik>0000741516</issuerCik>        <issuerName>AMERICAN NATIONAL BANKSHARES INC</issuerName>        <issuerTradingSymbol>amnb</issuerTradingSymbol>    </issuer>    <reportingOwner>        <reportingOwnerId>            <rptOwnerCik>0001368881</rptOwnerCik>            <rptOwnerName>Owen Claude B</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>11936 BELMONT PARK COURT</rptOwnerStreet1>            <rptOwnerStreet2></rptOwnerStreet2>            <rptOwnerCity>GLEN ALLEN</rptOwnerCity>            <rptOwnerState>VA</rptOwnerState>            <rptOwnerZipCode>23059</rptOwnerZipCode>            <rptOwnerStateDescription></rptOwnerStateDescription>        </reportingOwnerAddress>        <reportingOwnerRelationship>            <isDirector>1</isDirector>            <isOfficer>0</isOfficer>            <isTenPercentOwner>0</isTenPercentOwner>            <isOther>0</isOther>        </reportingOwnerRelationship>    </reportingOwner>    <nonDerivativeTable>        <nonDerivativeTransaction>            <securityTitle>                <value>American National Bankshares Inc.</value>            </securityTitle>            <transactionDate>                <value>2010-09-02</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>P</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionTimeliness>                <value></value>            </transactionTimeliness>            <transactionAmounts>                <transactionShares>                    <value>180</value>                </transactionShares>                <transactionPricePerShare>                    <value>20.78</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>A</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>11997.3618</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeHolding>            <securityTitle>                <value>American National Bankshares Inc.</value>            </securityTitle>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>4200</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>I</value>                </directOrIndirectOwnership>                <natureOfOwnership>                    <value>by wife</value>                </natureOfOwnership>            </ownershipNature>        </nonDerivativeHolding>    </nonDerivativeTable>    <ownerSignature>        <signatureName>Carolyn Compton</signatureName>        <signatureDate>2010-09-07</signatureDate>    </ownerSignature></ownershipDocument>
