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

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-05-11</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000351817</issuerCik>
        <issuerName>SWIFT ENERGY CO</issuerName>
        <issuerTradingSymbol>SFY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188673</rptOwnerCik>
            <rptOwnerName>CANNON DEANNA L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>104 S UNION STREET</rptOwnerStreet1>
            <rptOwnerStreet2>STE 209</rptOwnerStreet2>
            <rptOwnerCity>TRAVERSE CITY</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>49684</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>Karen Bryant POA for Deanna L. Cannon</signatureName>
        <signatureDate>2004-05-13</signatureDate>
    </ownerSignature>
</ownershipDocument>

