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

    <schemaVersion>X0202</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2004-08-03</periodOfReport>

    <dateOfOriginalSubmission>2004-08-13</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001094561</issuerCik>
        <issuerName>QUOVADX INC</issuerName>
        <issuerTradingSymbol>QVDXE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224015</rptOwnerCik>
            <rptOwnerName>ZAJAC THOMAS H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6400 SOUTH FIDDLER'S GREEN CIRCLE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1000</rptOwnerStreet2>
            <rptOwnerCity>ENGLEWOOD</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle>EVP and President of</officerTitle>
            <otherText>CareScience Division</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5611</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-11-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>60000</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.12</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-06-28</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>75000</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Grant to reporting person of an option to buy 60,000 shares of Quovadx common stock under the Company's Amended and Restated 2000 Nonstatutory Stock Option Plan.</footnote>
        <footnote id="F2">The shares underlying the option, listed in column 3 of Table II, shall vest as follows: 25% of the shares subject to the option shall vest on November 21, 2004, and 1/48th of the shares subject to the option shall vest each month thereafter, provided that the reporting person continues to be an employee of the Company on such dates.</footnote>
        <footnote id="F3">Grant to reporting person of option to buy 75,000 shares of Quovadx common stock under the Company's Amended and Restated 200 Nonstatutory Stock Option Plan.</footnote>
        <footnote id="F4">1/36th of the shares underlying the option, listed in column 3 of Table II, shall vest monthly beginning August 1, 2004, provided that the reporting person continues to be an employee of the Company on such dates.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Linda K. Wackwitz as Attorney-in-Fact for Thomas H. Zajac</signatureName>
        <signatureDate>2004-08-16</signatureDate>
    </ownerSignature>
</ownershipDocument>

