<SEC-DOCUMENT>0001021462-15-000032.txt : 20151207
<SEC-HEADER>0001021462-15-000032.hdr.sgml : 20151207
<ACCEPTANCE-DATETIME>20151207185808
ACCESSION NUMBER:		0001021462-15-000032
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20151203
FILED AS OF DATE:		20151207
DATE AS OF CHANGE:		20151207

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:			DAMERIS PETER T
		CENTRAL INDEX KEY:			0001021462

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35636
		FILM NUMBER:		151273828

	MAIL ADDRESS:	
		STREET 1:		C/O ON ASSIGNMENT INC
		STREET 2:		26745 MALIBU HILLS ROAD
		CITY:			CALABASAS
		STATE:			CA
		ZIP:			91301
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
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<DESCRIPTION>PRIMARY DOCUMENT
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    <periodOfReport>2015-12-03</periodOfReport>

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        <issuerCik>0000890564</issuerCik>
        <issuerName>ON ASSIGNMENT INC</issuerName>
        <issuerTradingSymbol>ASGN</issuerTradingSymbol>
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            <rptOwnerName>DAMERIS PETER T</rptOwnerName>
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            <rptOwnerStreet1>ON ASSIGNMENT, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>26745 MALIBU HILLS ROAD</rptOwnerStreet2>
            <rptOwnerCity>CALABASAS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91301</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
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        <nonDerivativeTransaction>
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                <value>Common Stock</value>
            </securityTitle>
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                <value>2015-12-04</value>
            </transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>5997.0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>47.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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    <derivativeTable>
        <derivativeTransaction>
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                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
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                <value>11.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-12-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>25144.0</value>
                </transactionShares>
                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F3"/>
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            <expirationDate>
                <value>2017-01-02</value>
            </expirationDate>
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                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
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                </underlyingSecurityShares>
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                    <value>D</value>
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    <footnotes>
        <footnote id="F1">The $47.504366 share price is a weighted average of numerous open market trades made at prices ranging from $47.27 to $47.96.</footnote>
        <footnote id="F2">The $46.893001 share price is a weighted average of numerous open market trades made at prices ranging from $46.80 to $47.12.</footnote>
        <footnote id="F3">Option Grant Vesting Schedule : 11% on 1/2/07; 1.83% monthly in 2007; 2.83% monthly in 2008; 1.83% monthly in 2009; .92% monthly in 2010.  All vestings shall occur on the last day of the month.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: James L. Brill, CAO For: Peter T. Dameris</signatureName>
        <signatureDate>2015-12-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
