<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-12-16</periodOfReport>
    <issuer>
        <issuerCik>0000884144</issuerCik>
        <issuerName>FORGENT NETWORKS  INC</issuerName>
        <issuerTradingSymbol>FORG</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181536</rptOwnerCik>
            <rptOwnerName>PETERSON JAY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>108 WILD BASIN ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78746</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>VP FINANCE AND CFO</officerTitle></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>NON-QUALIFIED STOCK OPTION (right to buy)</value></securityTitle><conversionOrExercisePrice><value>2.95</value></conversionOrExercisePrice><transactionDate><value>2003-12-16</value><footnoteId id="F1"/></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>8125</value></transactionShares><transactionPricePerShare><value>2.95</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-11-03</value></exerciseDate><expirationDate><value>2013-11-03</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>COMMON STOCK</value></underlyingSecurityTitle><underlyingSecurityShares><value>8125</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>273992</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>INCENTIVE STOCK OPTION</value></securityTitle><conversionOrExercisePrice><value>2.95</value></conversionOrExercisePrice><transactionDate><value>2003-12-16</value><footnoteId id="F1"/></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>21875</value></transactionShares><transactionPricePerShare><value>2.95</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-11-03</value></exerciseDate><expirationDate><value>2013-11-03</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>COMMON STOCK</value></underlyingSecurityTitle><underlyingSecurityShares><value>21875</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>295867</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Options were granted 11/03/03 and the reporting person was notified of the grant on 12/16/03.</footnote></footnotes><remarks/><ownerSignature><signatureName>JAY PETERSON</signatureName><signatureDate>2003-12-17</signatureDate></ownerSignature></ownershipDocument>

