-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 ECX62qn2KrAPZKlcRnbyKqqc7dbflffadyKNDZkgXJZOQwUpykaJB/ggCP+7WUUA
 dOnR8etjZa/DbXF2Gi4WKg==

<SEC-DOCUMENT>0001179110-11-000492.txt : 20110104
<SEC-HEADER>0001179110-11-000492.hdr.sgml : 20110104
<ACCEPTANCE-DATETIME>20110104202147
ACCESSION NUMBER:		0001179110-11-000492
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091229
FILED AS OF DATE:		20110104
DATE AS OF CHANGE:		20110104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Summers Scott E.
		CENTRAL INDEX KEY:			0001442482

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34145
		FILM NUMBER:		11508613

	MAIL ADDRESS:	
		STREET 1:		26000 COMMERCENTRE DR.
		CITY:			LAKE FOREST
		STATE:			CA
		ZIP:			92630

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Primoris Services CORP
		CENTRAL INDEX KEY:			0001361538
		STANDARD INDUSTRIAL CLASSIFICATION:	WATER, SEWER, PIPELINE, COMM AND POWER LINE CONSTRUCTION [1623]
		IRS NUMBER:				204743916
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		26000 COMMERCENTRE DRIVE
		CITY:			LAKE FOREST
		STATE:			CA
		ZIP:			92630
		BUSINESS PHONE:		(949) 598-9242

	MAIL ADDRESS:	
		STREET 1:		26000 COMMERCENTRE DRIVE
		CITY:			LAKE FOREST
		STATE:			CA
		ZIP:			92630

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Rhapsody Acquisition Corp.
		DATE OF NAME CHANGE:	20060503

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Summers Family Trust
		CENTRAL INDEX KEY:			0001442334

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34145
		FILM NUMBER:		11508614

	BUSINESS ADDRESS:	
		STREET 1:		26000 COMMERCENTRE DR.
		CITY:			LAKE FOREST
		STATE:			CA
		ZIP:			92630
		BUSINESS PHONE:		949-598-9242

	MAIL ADDRESS:	
		STREET 1:		26000 COMMERCENTRE DR.
		CITY:			LAKE FOREST
		STATE:			CA
		ZIP:			92630
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-12-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001442334</rptOwnerCik>
            <rptOwnerName>Summers Family Trust</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PRIMORIS SERVICES CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>26000 COMMERCE CENTRE DRIVE</rptOwnerStreet2>
            <rptOwnerCity>LAKE FOREST</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92630</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>See remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001442482</rptOwnerCik>
            <rptOwnerName>Summers Scott E.</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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>See remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-12-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9750</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1470422</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>8055</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1462367</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-12-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9750</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Scott Summers' children's trusts.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>8055</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17805</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Scott Summers' children's trusts.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On December 29, 2009 Scott Summers Family Trust gifted 3,250 shares each of Common Stock to his children's trusts: 1)Patrick Summers, Trustee of the Christen Leigh Summers Trust 12/17/09; 2)Patrick Summers, Trustee of the Briana Lynn Summers Trust 12/17/09; 3)Patrick Summers, Trustee of the Danielle June Summers Trust 12/22/09. Total shares of common stock transferred 9,750.  Patrick Summers is the brother of Scott E. Summers.</footnote>
        <footnote id="F2">On December 30, 2010 Scott Summers Family Trust gifted 2,685 shares each of Common Stock to his children's trusts: 1)Patrick Summers, Trustee of the Christen Leigh Summers Trust 12/17/09; 2)Patrick Summers, Trustee of the Briana Lynn Summers Trust 12/17/09; 3)Patrick Summers, Trustee of the Danielle June Summers Trust 12/22/09. Total shares of common stock transferred 8,055.  Patrick Summers is the brother of Scott E. Summers.</footnote>
        <footnote id="F3">These shares are owned directly by the Summers Family Trust and indirectly by Scott E. Summers, as trustee of the trust.</footnote>
    </footnotes>

    <remarks>Member of 13(d) group owning more than 10%.</remarks>

    <ownerSignature>
        <signatureName>/s/ Peter J. Moerbeek, by power of attorney</signatureName>
        <signatureDate>2011-01-04</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Peter J. Moerbeek, by power of attorney</signatureName>
        <signatureDate>2011-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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