-----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,
 Sv2tb1N4fw05rmXUsfQa2iSWMJXJt4JQD3Y6QN6Nlz4WK9sN1e33flsPWeUXYeQY
 E3qMrXbXLw6DhJxDaUdErQ==

<SEC-DOCUMENT>0001179110-09-010315.txt : 20090701
<SEC-HEADER>0001179110-09-010315.hdr.sgml : 20090701
<ACCEPTANCE-DATETIME>20090701153901
ACCESSION NUMBER:		0001179110-09-010315
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090630
FILED AS OF DATE:		20090701
DATE AS OF CHANGE:		20090701

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROTHENBERG ALAN I
		CENTRAL INDEX KEY:			0001238629

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09627
		FILM NUMBER:		09922455

	MAIL ADDRESS:	
		STREET 1:		633 WEST FIFTH ST.
		STREET 2:		SUITE 4000
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ZENITH NATIONAL INSURANCE CORP
		CENTRAL INDEX KEY:			0000109261
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				952702776
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		21255 CALIFA ST
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367
		BUSINESS PHONE:		8187131000
</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>2009-06-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000109261</issuerCik>
        <issuerName>ZENITH NATIONAL INSURANCE CORP</issuerName>
        <issuerTradingSymbol>ZNT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001238629</rptOwnerCik>
            <rptOwnerName>ROTHENBERG ALAN I</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1ST CENTURY BANK, N.A.</rptOwnerStreet1>
            <rptOwnerStreet2>1875 CENTURY PARK EAST, SUITE 1450</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90067</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-06-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>21.69</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-07-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2414.90</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>21.74</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2414.90</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23579.45</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Held in the reporting person's pension trust, for which he is trustee.</footnote>
        <footnote id="F2">Each share of phantom stock is a deferred stock unit payable only in cash and is the economic equivalent of a share of the Issuer's common stock. Reporting Person's director compensation is deferred into deferred stock units pursuant to the terms of the Zenith National Insurance Corp. 2003 Non-Employee Director Deferred Compensation Plan. Dividends payable on the common stock are deemed received on the deferred stock units and reinvested in deferred stock units. Deferred stock units become payable upon the Reporting Person's termination of service as a director and are payable only in cash (not in stock) in a lump sum or in installments over five or ten years at the Reporting Person's election made at the time of the deferral. Earlier distribution of all or part of the deferred stock units may also be elected if such early distribution is after 24 months from the Reporting Person's election to defer his compensation into deferred stock units.</footnote>
        <footnote id="F3">Reporting Person's director compensation deferred into deferred stock units.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Hyman J. Lee Jr., attorney-in-fact</signatureName>
        <signatureDate>2009-07-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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