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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-12-29</periodOfReport>

    <issuer>
        <issuerCik>0000916459</issuerCik>
        <issuerName>GARDNER DENVER INC</issuerName>
        <issuerTradingSymbol>GDI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001299140</rptOwnerCik>
            <rptOwnerName>PETRATIS DAVID D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SCHNEIDER ELECTRIC</rptOwnerStreet1>
            <rptOwnerStreet2>1415 ROSELLE ROAD</rptOwnerStreet2>
            <rptOwnerCity>PALATINE</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stk Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-12-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>332.2</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>37.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>332.2</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5230.5</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The security converts to common stock on a one-for-one basis.</footnote>
        <footnote id="F2">As a result of an election by the reporting person to defer compensation, 285.7 phantom stock units were accrued under the Phantom Plan.</footnote>
        <footnote id="F3">The cash value of these units will be distributed to the director or beneficiary on the first day of the month following the date upon which the director ceases to be a director of the Company for any reason, (or in no more than twelve installments beginning on the aforementioned date) pursuant to the Company's Phantom Stock Plan for Outside Directors (the &quot;Phantom Plan&quot;).</footnote>
        <footnote id="F4">Cummulative phantom stock units accumulated by the reporting person during his tenure on the Board of Directors.</footnote>
    </footnotes>

    <remarks>Tracy D. Pagliara, Attorney-in-fact for David D. Petratis pursuant to a Power of Attorney dated July 29, 2004 and filed on July 29, 2004.</remarks>

    <ownerSignature>
        <signatureName>/s/Tracy D. Pagliara, Attorney-in-fact</signatureName>
        <signatureDate>2007-01-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
