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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-31</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001191933</rptOwnerCik>
            <rptOwnerName>SCHUMACHER DIANE K</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>COOPER INDUSTRIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>600 TRAVIS SUITE 5800</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77002</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>2007-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>52.8</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.14</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>52.8</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3522.6</value>
                    <footnoteId id="F3"/>
                </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">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="F3">Cumulative phantom units accumulated by director during her Board tenure.</footnote>
    </footnotes>

    <remarks>Tracy D. Pagliara, Attorney-in-fact for Diane K. Schumacher, pursuant to Power of Attorney dated August 29, 2002 and filed with the SEC on October 2, 2002.</remarks>

    <ownerSignature>
        <signatureName>/s/Tracy D. Pagliara</signatureName>
        <signatureDate>2008-01-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
