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

    <documentType>4</documentType><periodOfReport>2003-11-06</periodOfReport>
    <issuer>
        <issuerCik>0000044471</issuerCik>
        <issuerName>GUILFORD MILLS INC</issuerName>
        <issuerTradingSymbol>GMIL</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235206</rptOwnerCik>
            <rptOwnerName>MACKINNON ALAN R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GUILFORD MILLS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>6001 WEST MARKET STREET</rptOwnerStreet2>
            <rptOwnerCity>GREENSBORO</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>27409</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Vice President, Sales/Auto</officerTitle></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>4.00</value></conversionOrExercisePrice><transactionDate><value>2003-11-06</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>15000</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F1"/></exerciseDate><expirationDate><value>2013-06-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock </value></underlyingSecurityTitle><underlyingSecurityShares><value>15000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>15000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">The option vests in three equal annual installments beginning on June 24, 2004.</footnote></footnotes><remarks/><ownerSignature><signatureName>Robert A. Emken, Jr., Attorney-in-Fact</signatureName><signatureDate>2003-11-07</signatureDate></ownerSignature></ownershipDocument>

