<SUBMISSION>
<ACCESSION-NUMBER>0001179110-09-006394
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20090206
<FILING-DATE>20090410
<DATE-OF-FILING-DATE-CHANGE>20090410
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>BROWN PETER CUMMINS
<CIK>0001461814
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-34145
<FILM-NUMBER>09744784
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>28000 COMMERCENTRE DRIVE
<CITY>LAKE FOREST
<STATE>CA
<ZIP>92630
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>Primoris Services CORP
<CIK>0001361538
<ASSIGNED-SIC>1623
<IRS-NUMBER>204743916
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>26000 COMMERCENTRE DRIVE
<CITY>LAKE FOREST
<STATE>CA
<ZIP>92630
<PHONE>(949) 598-9242
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>26000 COMMERCENTRE DRIVE
<CITY>LAKE FOREST
<STATE>CA
<ZIP>92630
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>Rhapsody Acquisition Corp.
<DATE-CHANGED>20060503
</FORMER-COMPANY>
</ISSUER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2009-02-06</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001361538</issuerCik>
        <issuerName>Primoris Services CORP</issuerName>
        <issuerTradingSymbol>PRIM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001461814</rptOwnerCik>
            <rptOwnerName>BROWN PETER CUMMINS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PRIMORIS SERVICES CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>26000 COMMERCENTRE DRIVE</rptOwnerStreet2>
            <rptOwnerCity>LAKE FOREST</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92630</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Peter J. Moerbeek, by power of attorney</signatureName>
        <signatureDate>2009-04-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
