<SEC-DOCUMENT>0001179110-18-004341.txt : 20180314
<SEC-HEADER>0001179110-18-004341.hdr.sgml : 20180314
<ACCEPTANCE-DATETIME>20180314192825
ACCESSION NUMBER:		0001179110-18-004341
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180313
FILED AS OF DATE:		20180314
DATE AS OF CHANGE:		20180314

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Thor James E
		CENTRAL INDEX KEY:			0001300922

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20797
		FILM NUMBER:		18690693

	MAIL ADDRESS:	
		STREET 1:		C/O RUSH ENTERPRISES, INC.
		STREET 2:		P. O. BOX 34630
		CITY:			SAN ANTONIO
		STATE:			TX
		ZIP:			78265

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RUSH ENTERPRISES INC \TX\
		CENTRAL INDEX KEY:			0001012019
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-AUTO DEALERS & GASOLINE STATIONS [5500]
		IRS NUMBER:				741733016
		STATE OF INCORPORATION:			TX
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		555 IH 35 SOUTH
		CITY:			NEW BRAUNFELS
		STATE:			TX
		ZIP:			78130
		BUSINESS PHONE:		8306265200

	MAIL ADDRESS:	
		STREET 1:		555 IH 35 SOUTH
		CITY:			NEW BRAUNFELS
		STATE:			TX
		ZIP:			78130
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-03-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001012019</issuerCik>
        <issuerName>RUSH ENTERPRISES INC \TX\</issuerName>
        <issuerTradingSymbol>RUSH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001300922</rptOwnerCik>
            <rptOwnerName>Thor James E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>555 IH 35 SOUTH, SUITE 500</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW BRAUNFELS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-03-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>844</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>38.83</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>45361</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares reported are shares not distributed to the reporting person in order to satisfy the reporting person's tax obligations with respect to vesting associated with the grant that occurred on March 13, 2015.</footnote>
        <footnote id="F2">Includes unvested restricted stock units.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Steven L. Keller, Attorney in Fact for James E. Thor</signatureName>
        <signatureDate>2018-03-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
