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

    <schemaVersion>X0202</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2005-12-06</periodOfReport>

    <dateOfOriginalSubmission>2005-12-06</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001329919</issuerCik>
        <issuerName>Vocus, Inc.</issuerName>
        <issuerTradingSymbol>VOCS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001346053</rptOwnerCik>
            <rptOwnerName>Lazard Technology Partners</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5335 WISCONSIN AVENUE, NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 410</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001352821</rptOwnerCik>
            <rptOwnerName>Lazard Alternative Investments LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5335 WISCONSIN AVENUE, NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 410</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001352790</rptOwnerCik>
            <rptOwnerName>LTP II GenPar LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5335 WISCONSIN AVENUE, NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 410</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001352788</rptOwnerCik>
            <rptOwnerName>LTP II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5335 WISCONSIN AVENUE, NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 410</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001352787</rptOwnerCik>
            <rptOwnerName>Planitzer Russell E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5335 WISCONSIN AVENUE, NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 410</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001352786</rptOwnerCik>
            <rptOwnerName>Rana Manu S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5335 WISCONSIN AVENUE, NW</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 410</rptOwnerStreet2>
            <rptOwnerCity>WASHINGTON</rptOwnerCity>
            <rptOwnerState>DC</rptOwnerState>
            <rptOwnerZipCode>20015</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2006-12-09</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2245570</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series C Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-12-09</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>448721</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock Warrant (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.77</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-12-20</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-01-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>88176</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock Warrant (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.85</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-01-31</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-01-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Series B Preferred Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>137344</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These securities are preferred stock of the Issuer and do not have an expiration date.  These securities will automatically convert into shares of the Issuer's Common Stock upon the filing of the Issuer's Fifth Amended and Restated Charter.</footnote>
        <footnote id="F2">Lazard Technology Partners II LP is the record holder of the securities and Lazard Alternative Investments LLC is the nominee for Lazard Technology Partners II LP with regard to such securities.  As the general partner of both Lazard Technology Partners II LP and Lazard Alternative Investments LLC, LTP II LP may be deemed a beneficial owner of the securities.  As the general partner of LTP II LP, LTP II GenPar LLC may also be deemed to be a beneficial owner of the securities.  In their capacities as principals and/or managing principals, as applicable, of LTP II GenPar LLC, each of Russell E. Planitzer and Manu S. Rana may also be deemed to be beneficial owners of the securities.  Each Joint Filer, other than Lazard Technology Partners II LP expressly disclaims beneficial ownership of the securities, except to the extent of his or its pecuniary interest therein, if any.</footnote>
    </footnotes>

    <remarks>This amended Form 3 amends a previous Form 3 and two Form 4s filed on behalf of Lazard Technology Partners II LP by including the additional Joint Filers listed on the attachment hereto.</remarks>

    <ownerSignature>
        <signatureName>Christopher A. Davis, Attorney-in-fact</signatureName>
        <signatureDate>2006-02-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
