<SEC-DOCUMENT>0001104659-14-088024.txt : 20141219
<SEC-HEADER>0001104659-14-088024.hdr.sgml : 20141219
<ACCEPTANCE-DATETIME>20141219215505
ACCESSION NUMBER:		0001104659-14-088024
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20141216
FILED AS OF DATE:		20141219
DATE AS OF CHANGE:		20141219

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ON ASSIGNMENT INC
		CENTRAL INDEX KEY:			0000890564
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-HELP SUPPLY SERVICES [7363]
		IRS NUMBER:				954023433
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		26745 MALIBU HILLS ROAD
		CITY:			CALABASAS
		STATE:			CA
		ZIP:			91301
		BUSINESS PHONE:		8188787900

	MAIL ADDRESS:	
		STREET 1:		26745 MALIBU HILLS ROAD
		CITY:			CALABASAS
		STATE:			CA
		ZIP:			91301

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hanson Theodore S.
		CENTRAL INDEX KEY:			0001550337

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35636
		FILM NUMBER:		141301237

	MAIL ADDRESS:	
		STREET 1:		26745 MALIBU HILLS ROAD
		CITY:			CALABASAS
		STATE:			CA
		ZIP:			91301
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>a4a.xml
<DESCRIPTION>4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2014-12-16</periodOfReport>

    <dateOfOriginalSubmission>2014-12-17</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000890564</issuerCik>
        <issuerName>ON ASSIGNMENT INC</issuerName>
        <issuerTradingSymbol>ASGN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001550337</rptOwnerCik>
            <rptOwnerName>Hanson Theodore S.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>26745 MALIBU HILLS ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CALABASAS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91301</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CFO, Apex, a sub of the issuer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>176.00</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>30.5000</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>297969.00</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The purpose of this amendment is to add this footnote which references the fact that the Executive Officer elected to satisfy his tax withholding obligations upon vesting by having the issuer withhold a number of vested shares equal to that of the officer's tax liability.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Power of Attorney, James. L Brill, CAO For: Theodore S. Hanson</signatureName>
        <signatureDate>2014-12-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
