<SEC-DOCUMENT>0000874238-18-000011.txt : 20180212
<SEC-HEADER>0000874238-18-000011.hdr.sgml : 20180212
<ACCEPTANCE-DATETIME>20180212135432
ACCESSION NUMBER:		0000874238-18-000011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180210
FILED AS OF DATE:		20180212
DATE AS OF CHANGE:		20180212

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BALLSCHMIEDE RONALD A
		CENTRAL INDEX KEY:			0001366918

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31993
		FILM NUMBER:		18595600

	MAIL ADDRESS:	
		STREET 1:		2103 RESEARCH FOREST DRIVE
		CITY:			THE WOODLANDS
		STATE:			TX
		ZIP:			77380

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			STERLING CONSTRUCTION CO INC
		CENTRAL INDEX KEY:			0000874238
		STANDARD INDUSTRIAL CLASSIFICATION:	HEAVY CONSTRUCTION OTHER THAN BUILDING CONST - CONTRACTORS [1600]
		IRS NUMBER:				251655321
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2751 CENTERVILLE RD.
		STREET 2:		SUITE 3131
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19803
		BUSINESS PHONE:		3024789170

	MAIL ADDRESS:	
		STREET 1:		20810 FERNBUSH LANE
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77073

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OAKHURST CO INC
		DATE OF NAME CHANGE:	19950831

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OAKHURST CAPITAL INC
		DATE OF NAME CHANGE:	19931130
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_151846165764501.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-02-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000874238</issuerCik>
        <issuerName>STERLING CONSTRUCTION CO INC</issuerName>
        <issuerTradingSymbol>STRL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001366918</rptOwnerCik>
            <rptOwnerName>BALLSCHMIEDE RONALD A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1800 HUGHES LANDING BLVD.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>THE WOODLANDS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77380</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2370</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.57</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>95015</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These shares were part of a restricted stock award, made pursuant to the Company's Stock Incentive Plan, a portion of which was released on February 10, 2018. The shares were retained by the Company at the election of the Reporting Person pursuant to a procedure approved by the Compensation Committee of the Board of Directors to satisfy the Company's tax withholding requirements, based on the closing price of the Company's common stock on the release date as permitted by the Plan.</footnote>
        <footnote id="F2">Of these shares, 29,665 shares are subject to restrictions on their sale or other transfer and to forfeiture under certain circumstances.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Craig B. Allen under a Power of Attorney</signatureName>
        <signatureDate>2018-02-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
