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

    <documentType>4</documentType><periodOfReport>2004-01-02</periodOfReport>
    <issuer>
        <issuerCik>0000931148</issuerCik>
        <issuerName>GRAFTECH INTERNATIONAL LTD</issuerName>
        <issuerTradingSymbol>GTI</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001066128</rptOwnerCik>
            <rptOwnerName>PLAYFORD GILBERT E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GRAFTECH INTERNATIONAL LTD.</rptOwnerStreet1>
            <rptOwnerStreet2>1521 CONCORD PIKE, SUITE 301</rptOwnerStreet2>
            <rptOwnerCity>WILMINGTON,</rptOwnerCity>
            <rptOwnerState>DE</rptOwnerState>
            <rptOwnerZipCode>19803</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>221400</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-02</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>3217</value></transactionShares><transactionPricePerShare><value>16.69</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>29497</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Compensation Deferral Plan.</value><footnoteId id="F1"/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>19378</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By IRA.</value><footnoteId id="F2"/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1200</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Spouse.  The reporting person disclaims beneficial ownership of these securities.</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeHolding><securityTitle><value>Time options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>30.5891</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F3"/></exerciseDate><expirationDate><value>2007-01-25</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>300000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>300000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Time options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>17.0625</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F4"/></exerciseDate><expirationDate><value>2008-09-28</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>300000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>300000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Time options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>8.56</value></conversionOrExercisePrice><exerciseDate><value>2002-12-15</value></exerciseDate><expirationDate><value>2010-12-15</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>300000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>300000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Time options (right to buy)</value></securityTitle><conversionOrExercisePrice><value>8.85</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F5"/></exerciseDate><expirationDate><value>2011-09-25</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>274000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>274000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding></derivativeTable><footnotes><footnote id="F1">Represents obligations whose value is based on the Common Stock under the Company's Compensation Deferral Program.  The reporting person disclaims beneficial ownership of such securities.  This disposition is required in connection with the reporting person's retirement as CEO of the Company in June 2003.  Under the Compensation Deferral Program, the reporting person is required to cash out and has elected to cash out over 10 years, which is the longest permitted period.</footnote><footnote id="F2">On July 1, 2003, the reporting person transferred 20,148 units representing 19,378 shares from the Company Stock Fund option of the UCAR Carbon Savings Plan to an IRA unaffiliated with the Company.  Such transfer was exempt pursuant to Rule 16b-3(c).</footnote><footnote id="F3">200,000 of such options became exercisable on June 22, 2000 and 100,000 of such options became exercisable on June 22, 2001.</footnote><footnote id="F4">Of such options, 100,000 vested on each of May 21, 1999, July 14, 1999 and September 29,1999.</footnote><footnote id="F5">Options were granted as part of an annual grant.  Of such options, 41,000 vested on September 25, 2001 and 233,000 vested on June 30, 2003 in connection with the reporting person's retirement as CEO of the Company in June 2003.</footnote></footnotes><remarks/><ownerSignature><signatureName>Karen G. Narwold, Attorney-in-fact for Gilbert E. Playford</signatureName><signatureDate>2004-01-06</signatureDate></ownerSignature></ownershipDocument>

