<SUBMISSION>
<ACCESSION-NUMBER>0001179110-07-013915
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20070627
<FILING-DATE>20070627
<DATE-OF-FILING-DATE-CHANGE>20070627
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>PROS Holdings, Inc.
<CIK>0001392972
<ASSIGNED-SIC>7371
<IRS-NUMBER>760168604
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>3100 MAIN STREET
<STREET2>SUITE 900
<CITY>HOUSTON
<STATE>TX
<ZIP>77002
<PHONE>713-335-5151
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3100 MAIN STREET
<STREET2>SUITE 900
<CITY>HOUSTON
<STATE>TX
<ZIP>77002
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>JMI EQUITY FUND III LP
<CIK>0001035818
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>07944739
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1119 ST PAUL ST
<CITY>BALTIMORE
<STATE>MD
<ZIP>21202
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>12680 HIGH BLUFF DR
<STREET2>SUITE 200
<CITY>SAN DIEGO
<STATE>CA
<ZIP>92130
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>JMI Associates III, L.L.C.
<CIK>0001401409
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>07944740
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>2 HAMILL ROAD
<STREET2>SUITE 272
<CITY>BALTIMORE
<STATE>MD
<ZIP>21210
<PHONE>4109510200
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2 HAMILL ROAD
<STREET2>SUITE 272
<CITY>BALTIMORE
<STATE>MD
<ZIP>21210
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2007-06-27</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001392972</issuerCik>
        <issuerName>PROS Holdings, Inc.</issuerName>
        <issuerTradingSymbol>PRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001401409</rptOwnerCik>
            <rptOwnerName>JMI Associates III, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2 HAMILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 272</rptOwnerStreet2>
            <rptOwnerCity>BALTIMORE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001035818</rptOwnerCik>
            <rptOwnerName>JMI EQUITY FUND III LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2 HAMILL ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 272</rptOwnerStreet2>
            <rptOwnerCity>BALTIMORE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2321280</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">JMI Equity Fund III, L.P. holds 2,321,280 shares of common stock of PROS Holdings, Inc.  JMI Associates III, LLC is the general partner of JMI Equity Fund III, L.P. and may be deemed to have a beneficial interest in the shares held by JMI Equity Fund III, L.P.  JMI Associates III, LLC disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>JMI Associates III, LLC, By Harry S. Gruner, Managing Member</signatureName>
        <signatureDate>2007-06-27</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>JMI Equity Fund III, L.P., By JMI Associates III, LLC, Its General Partner, By Harry S. Gruner, Managing Member</signatureName>
        <signatureDate>2007-06-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
