UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C.  20549

FORM 11-K

xANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.

For the Fiscal Year Ended December 31, 2006

OR

oTRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934.

For the transition period from               to               

Commission file number 1-9627

A.Full title of the plan and the address of the plan, if different from that of the issuer named below:

THE ZENITH 401(k) PLAN

B.Name of issuer of the securities held pursuant to the plan and the address of its principal executive office:

Zenith National Insurance Corp.
21255 Califa Street
Woodland Hills, CA  91367-5021

The Zenith 401(k) Plan
Report on Audited Financial Statements
and Supplemental Schedule
For the Years Ended December 31, 2006 and 2005

The Zenith 401(k) Plan
Financial Statements and Supplemental Schedule

Table of Contents

Financial Statements:

Supplemental Schedule:

Signature

Exhibit Index:

Exhibit 23.1 - Consent of Independent Registered Public Accounting Firm

All other schedules required by Section 2520.103-10 of the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974, as amended, have been omitted because they are not applicable.

Report of Independent Registered Public Accounting Firm

To the Participants and Administrative Committee of
The Zenith 401(k) Plan:

In our opinion, the accompanying statements of net assets available for benefits and the related statement of changes in net assets available for benefits present fairly, in all material respects, the net assets available for benefits of The Zenith 401(k) Plan (the “Plan”) at December 31, 2006 and 2005, and the changes in net assets available for benefits for the year ended December 31, 2006 in conformity with accounting principles generally accepted in the United States of America.  These financial statements are the responsibility of the Plan’s management. Our responsibility is to express an opinion on these financial statements based on our audits.  We conducted our audits of these statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement.  An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation.  We believe that our audits provide a reasonable basis for our opinion.

Our audits were conducted for the purpose of forming an opinion on the basic financial statements taken as a whole.  The supplemental schedule of assets (held at end of year) as of December 31, 2006 is presented for the purpose of additional analysis and is not a required part of the basic financial statements but is supplementary information required by the Department of Labor’s Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974.  This supplemental schedule is the responsibility of the Plan’s management.  The supplemental schedule has been subjected to the auditing procedures applied in the audits of the basic financial statements and, in our opinion, is fairly stated in all material respects in relation to the basic financial statements taken as a whole.

As discussed in Note 2, effective for plan years ended after December 15, 2006, FASB Staff Position Nos. AAG INV-1 and SOP 94-4-1, Reporting of Fully Benefit-Responsive Investment Contracts Held by Certain Investment Companies Subject to the AICPA Investment Company Audit Guide and Defined Contribution Health and Welfare and Pension Plans, was required to be implemented.  Therefore the presentation of the 2005 and 2006 financial statement amounts include the presentation of fair value with an adjustment to contract value for such investments.

/s/ PricewaterhouseCoopers LLP

Los Angeles, California
June 26, 2007

The Zenith 401(k) Plan
Statements of Net Assets Available for Benefits

As of December 31,	2006		2005
Assets:
Cash	$	508,893	$	89,018
Investments	94,224,518		49,071,443
Receivables:
Accrued dividend	132,380		32,131
Accrued interest			4,732
Contributions receivable:
Participant			293,136
Employer	84,426		200,689
Securities sold	10,421		30,887,607
Total receivables	227,227		31,418,295
Net assets available for benefits, at fair value	94,960,638		80,578,756
Adjustment from fair value to contract value for fully benefit-responsive investment contracts	243,681		(18,484		)
Net assets available for benefits	$	95,204,319	$	80,560,272

The accompanying notes are an integral part of this financial statement.

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The Zenith 401(k) Plan
Statement of Changes in Net Assets Available for Benefits

For the Year Ended December 31,	2006
Additions in net assets attributed to:
Investment income:
Dividends	$	3,402,722
Interest	94,575
Net appreciation in the fair value of investments	4,164,571
Total investment income	7,661,868
Contributions:
Employer	2,652,756
Participant	9,069,171
Rollovers	1,002,841
Total contributions	12,724,768
Total additions	20,386,636
Deductions in net assets attributed to:
Benefits paid to participants	(5,733,539		)
Fees	(9,050		)
Total deductions	(5,742,589		)
Net increase	14,644,047
Net assets available for benefits:
Beginning of year	80,560,272
End of year	$	95,204,319

The accompanying notes are an integral part of this financial statement.

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The Zenith 401(k) Plan
Notes to Financial Statements

1.     The Plan

General

The Zenith 401(k) Plan (“Plan”) is a qualified plan under Sections 401(a) and 401(k) of the Internal Revenue Code of 1986, as amended (“Code”) and is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”). The Plan gives participants the opportunity to manage the investment of assets allocated to their respective individual accounts. Therefore, the Plan is designed to comply with Section 404(c) of ERISA.

Participation in the Plan is offered to all employees of Zenith National Insurance Corp. (“Zenith National”) and those of its subsidiaries that elect to become “participating employers” (collectively, “Company”). Participants should refer to the Plan Documents for additional information relating to the Plan.

Administration

The Plan Administrative Committee is appointed by the Board of Directors of Zenith National and has responsibility for administration of the Plan, including supervision of the collection of contributions, delivery of such contributions to the trustee of the Plan and maintenance of necessary records. During 2006, Nationwide Trust acted as trustee of the Plan (“Trustee”) and The 401K Company acted as an agent of the Trustee and provided custodial and record keeping services for the Plan. During 2005, such services were provided by JP Morgan Chase Bank and Metropolitan Life Insurance Company (“MetLife”), respectively.

The trustee holds all assets of the Plan in a trust (“Trust”) created under an agreement dated as of December 30, 1996. The Trust agreement was amended on March 9, 2007 appointing The Charles Schwab Trust Company as the successor to Nationwide Trust Company effective as of April 1, 2007. The Trustee’s responsibilities include receipt of Plan contributions, investment and maintenance of Trust assets in the available funds, and distributions under the Plan of such amounts as the Administrative Committee shall direct from time to time.

Eligibility

All newly hired employees are eligible to participate in the Plan as of the first of the month coinciding with, or next following, his or her date of hire. There are no age restrictions.

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Contributions

Participants may elect to contribute between 1% to 50% of their compensation up to a maximum of $15,000 for 2006 and $14,000 for 2005 (“Salary Reduction Contributions”). The maximum is adjusted each year for increases in the cost of living, as provided in applicable regulations of the Code. This annual amount is an aggregate limitation that applies to all of an individual’s Salary Reduction Contributions and similar contributions under other plans. The Company contributes an amount equal to 50% of the participant’s contribution amount (“Matched Contributions”). Matched contributions are defined as the participant’s contribution equal to the first 6% of his or her annual compensation. The Company’s matching contribution shall not exceed 3% of a participant’s annual compensation.

Compensation includes wages, bonuses, commissions, overtime pay and elective deferrals. Participants may allocate their Salary Reduction Contributions among investment options in such percentages as they determine. One of the investment options is the Zenith Company Stock Fund, which invests solely in the common stock, $1.00 par value per share, of Zenith National and participants may direct no more than 20% of each contribution to the Zenith Company Stock Fund. The Company’s matching contributions for a participant are directed to the same investment options and in the same proportion as that participant directs Salary Reduction Contributions.

The value of each fund is determined daily and participants are able to transfer amounts between funds on any business day, except that amounts may only be transferred out of, but not into, the Zenith Company Stock Fund. Further, any Company matching contributions made to the Zenith Company Stock Fund prior to February 15, 2002 may not be transferred until the participant is 40 years and older with ten years of service. These funds are considered nonparticipant-directed investments.

Participant Accounts

Each participant’s account is credited with: (1) Salary Reduction Contributions, (2) participant rollover contributions from non-Company plans, (3) Company matching contributions, and (4) fund earnings. Allocations of earnings are based on account balances, as defined in the Plan Documents.

Vesting

Each participant has an immediate, fully vested right to receive all Salary Reduction Contributions and earnings thereon upon termination from the Company or upon separation caused by death of the participant. All Company matching contributions vest over a five-year graduated vesting schedule of 20% per year. However, irrespective of the vesting schedule, a participant is fully vested upon his or her death, disability or attainment of age 65.

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Forfeitures

Upon termination of service, a participant forfeits any nonvested Company matching contributions. Such forfeitures are used first to reinstate participant account balances previously forfeited, which are subject to reinstatement under the terms of the Plan. Any remaining unused forfeitures are used to reduce current or future Company matching contributions to the Plan.

In 2006 and 2005, Company matching contributions were reduced by $342,575 and $108,750, respectively, from forfeited nonvested accounts. At December 31, 2006 and 2005, forfeited nonvested accounts totaled $16,156 and $36,771, respectively.

Withdrawals Prior to Termination of Employment

Except in limited circumstances, participants may not make withdrawals from their accounts while employed by the Company. Hardship withdrawals of a participant’s Salary Reduction Contributions are permitted only if a participant has an immediate and extraordinary financial need (as determined under Section 401(k)(2)(B)(IV) of the Code) and that need cannot be satisfied from other resources of the participant. Participants are entitled to withdraw amounts that they had rolled over into the Plan. In addition, participants who reach 59-1/2 years may take an in-service withdrawal of the vested portion of the individual accounts.

Participant Loans

Participants may borrow from their Salary Reduction Contributions accounts and rollover accounts. The minimum amount that may be borrowed is $1,000. The maximum amount that may be borrowed is the lesser of (a) 50% of the combined balances of their Salary Reduction Contributions accounts and rollover accounts, or (b) $50,000, reduced by the highest outstanding loan balance during the last 12 months. Participants may not obtain a loan of Company matching contributions. Loan transactions are treated as a transfer to (from) the investment fund from (to) the participant loans receivable. Loan terms range from 1 to 5 years or up to 30 years for the purchase of a principal residence. The loans are secured by the balance in the participant’s account. Interest will be charged on the loan, generally equal to the applicable treasury note rate plus 4% determined as of the close of the last Monday of the calendar month preceding the calendar month in which the loan is made. Principal and interest are paid ratably through payroll deductions. Upon termination of employment, participants are required to pay the outstanding loan amount in full.

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Payment of Benefits

If a distribution is made upon termination of employment, retirement, permanent disability that is or death, a participant receives (1) cash with respect to the portion of the individual account not invested in the Zenith Company Stock Fund and (2) at the participant’s election, cash or shares of Zenith National common stock, plus cash in lieu of any fractional shares, with respect to the Zenith Company Stock Fund. Payments are generally processed twice a month.

Expenses

The Plan provides that all expenses of the Plan (i.e., legal, accounting, administration and brokerage fees) will be paid by the Company, with the exception of fees paid to The 401K Company and expenses related to the administration of the mutual funds offered as investment alternatives. Expenses related to the administration of the mutual funds will be paid by the respective mutual funds, and will be reflected in the overall investment returns of such funds.

Termination

While the Company has not expressed an intent to terminate the Plan, it may do so at any time. Upon such termination, each participant would be 100% vested in his or her Company matching contributions.

2.     Summary of Significant Accounting Policies

Basis of Accounting

The financial statements of the Plan are prepared on the accrual basis of accounting in conformity with accounting principles generally accepted in the United States of America (“GAAP”).

As described in Financial Accounting Standards Board Staff Position, FSP AAG INV-1 and SOP 94-4-1, “Reporting of Fully Benefit-Responsive Investment Contracts Held by Certain Investment Companies Subject to the AICPA Investment Company Guide and Defined-Contribution Health and Welfare and Pension Plans” (“FSP”), investment contracts held by a defined-contribution plan are required to be reported at fair value. However, contract value is the relevant measurement attribute for that portion of the net assets available for benefits of a defined-contribution plan attributable to fully benefit-responsive investment contracts because contract value is the amount participants would receive if they were to initiate permitted transactions under the terms of the plan. As required by the FSP, the Statement of Net Assets Available for Benefits presents the fair value of the investment contracts as well as the adjustment of the fully benefit responsive investment contracts from fair value to contract value. The Statement of Changes in Net Assets Available for Benefits is prepared on a contract value basis. This FSP was adopted effective December 31, 2006.

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Use of Estimates

The preparation of the financial statements in conformity with GAAP requires the Plan’s management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of additions to and deductions from net assets during the reporting period. Actual results could differ from those estimates.

Investment Valuation and Income Recognition

The accounting for the Plan’s investment in the Zenith Company Stock Fund is the unit valuation method. The total value of the fund fluctuates depending upon the amount of interest earned on cash held in the fund, dividends paid on Zenith National common stock, realized gains and losses on the sale of Zenith National common stock, and unrealized appreciation or depreciation in the value of Zenith National common stock. The value of the Zenith Company Stock Fund is determined using the daily closing price of Zenith National common stock on the New York Stock Exchange.

Investments in shares of registered investment companies (mutual funds) are valued at quoted market prices, which represent the net asset value of shares held by the Plan. The investments in the pooled separate accounts, common funds or collective trust are valued at the net asset value of the account, fund or trust’s shares held by the Plan at year end.

Dividends and capital gains distributions declared by a mutual fund are allocated to each individual participant holding units in the mutual fund. Each participant’s shares as of a record date are multiplied by the dividend rate declared by the mutual fund. Certain funds declare a daily dividend rate and each day is a record date for those funds. At the end of the month, each participant’s account balance for each day of the month is credited with each day’s dividend based on the rates declared.

Generally, interest, dividends and capital gain distributions are allocated to a participant’s account in a mutual fund based on the number of units the participant holds in that mutual fund compared to total units outstanding for that mutual fund.

Purchases and sales of securities are reflected on a trade-date basis. Gains or losses on sales of securities are computed on an average-cost basis. Net appreciation in the fair value of investments disclosed in the statement of changes in net assets available for benefits consists of realized gains or losses and unrealized appreciation or depreciation on investments.

The Plan allows participants to invest in a stable value investment option.  Beginning April 1, 2006, this option was The Galliard Managed Customized Stable Value Fund (“Galliard Fund”). The Galliard Fund invests in security-backed contracts and the Wells Fargo Stable Return Fund G. From 2005 through March 31, 2006, the Plan’s stable value investment

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option was The MetLife Stock Market Index Guarantee Account (“MetLife Fund”) offered under the MetLife program.

The Galliard Fund’s principal objective is to protect principal while providing a higher rate of return than shorter maturity investments, such as money market funds or certificates of deposit. To achieve this, the Galliard Fund invests in instruments which are not expected to experience significant price fluctuation in most economic or interest rate environments.  However, there is no assurance that this objective can be achieved.

The fair value of a security-backed contract includes the value of the underlying securities and the value of the wrapper contract. The fair value of a wrapper contract is the replacement cost, and is based on the wrapper contract price.  The fair value of the Wells Fargo Stable Return Fund G is determined using a conversion ratio from contract value to fair value based on the underlying audited financial statements of the Wells Fargo Stable Return Fund G.

The Galliard Fund’s average yield and participant crediting interest rates as of December 31, 2006 were 5.23% and 5.07%, respectively. The crediting interest rate is based on an agreed-upon formula with Galliard but cannot be less than zero. Such interest rates are reviewed on a quarterly basis for resetting. There are no reserves against contract value for credit risk of the contract issuer or otherwise.

The crediting rate will track current market yields on a trailing basis.  The rate reset allows the contract value to converge with the fair value of the underlying portfolio over time, assuming the portfolio continues to earn the current yield for a period of time equal to the current portfolio duration.

To the extent that the underlying portfolio has unrealized and/or realized gains/losses, a negative/positive adjustment is made to the adjustment from fair value to contract value under contract value accounting.  As a result, the future crediting rate may be lower/higher over time than the then-current market rates.

Security-backed contracts generally provide for withdrawals associated with certain events which are not in the ordinary course of the Galliard Fund’s operations.  These withdrawals are paid with a market value adjustment applied to the withdrawal as defined in the investment contract. Events which may trigger a market value adjustment may include all or a portion of the following:

·Material amendments to the Galliard Fund’s structure or administration;

·Changes to the participating plan’s competing investment options including the elimination of equity wash provisions;

·Complete or partial termination of the Galliard Fund, including a merger with another fund;

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·The failure of the Galliard Fund to qualify for exemption from federal income taxes or any required prohibited transaction exemption under ERISA;

·Any change in law, regulation, ruling administrative or judicial position, or accounting requirement applicable to the Galliard Fund;

·The delivery of any communication to plan participants designed to influence a participant not to invest in the Galliard Fund.

At this time, the Company or the Plan Administrator does not believe that the occurrence of any such value event, which would limit the Plan’s ability to transact at contract value with participants, is probable.

If the Galliard Fund defaults in its obligations under the contract (including the security-backed contract issuer’s determination that the agreement constitutes a non-exempt prohibited transaction as defined under ERISA), and such default is not corrected within the time permitted by the contract, then the contract may be terminated by the security-backed contract issuer and the Galliard Fund will receive the fair value as of the date of termination.

The MetLife Fund was a pooled separate account. The value of the separate account was determined at the close of each business day based on market value. The value of the account was expressed in “units.” The units were net of daily investment management expenses. The “unit value” was the fair value of one unit, determined as of the end of each year.

Participant loans are valued at their outstanding balances, which approximates fair value.

Contributions

Salary Reduction Contributions and Company matching contributions are recorded in the period that a participant’s payroll deduction is made.

Benefits

Benefits are recorded when paid.

Reclassifications

Certain prior year amounts have been reclassified based upon the retroactive adoption of the FSP to conform to the current year presentation.

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Recently Issued Accounting Pronouncements

In September 2006, the FASB issued Statement No. 157, “Fair Value Measurements” (“SFAS No. 157”), which provides a common definition of fair value and establishes a framework to make the measurement of fair value more consistent and comparable. SFAS No. 157 also requires expanded disclosures about (1) the extent to which companies measure assets and liabilities at fair value, (2) the methods and assumptions used to measure fair value and (3) the effect of fair value measures on earnings. The Plan will adopt SFAS No. 157 on January 1, 2008 and it is expected that the adoption will not have a material effect on the Plan’s net assets available for benefits.

In September 2006, the Securities and Exchange Commission issued Staff Accounting Bulletin No. 108, “Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements” (“SAB 108”). SAB 108 provides interpretive guidance on how the effects of prior-year uncorrected misstatements should be considered when quantifying misstatements in the current year financial statements. SAB 108 requires registrants to quantify misstatements by analyzing the impact on both the Statement of Net Assets Available for Benefits and Statement of Changes in Net Assets Available for Benefits and evaluating whether either approach results in a misstatement that, when all relevant quantitative and qualitative factors are considered, is material. The adoption of SAB 108 as of December 31, 2006 did not have a material effect on the Plan’s net assets available for benefits.

3.     Investments

The following are the individual investments, at fair value, that represent 5% or more of net assets available for Plan benefits:

	As of December 31,
	2006		2005
Galliard Managed Customized Stable Value Fund	$	20,388,597
Zenith Company Stock Fund (*)	17,742,722		$	17,531,935
American Funds EuroPacific Growth Fund	13,166,996		8,869,633
Hotchkis & Wiley Large Cap Value I	12,048,759
American Funds Growth Fund of America	8,556,862
RS Partners Fund	5,554,389
Vanguard Explorer	5,063,522
State Street S&P Index L	4,773,229
MetLife GFIA			20,530,951

(*)— Zenith Company Stock Fund balance includes both participant and nonparticipant-directed investments (see Note 4). Since the Zenith Company Stock Fund invests solely in the common stock of Zenith National, investments in Zenith Company Stock Fund represented transactions with parties-in-interest for which a statutory exemption exists.

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The Plan’s investments (including gains and losses on investments bought and sold, as well as held during the year) appreciated in value in the year ended December 31, 2006 as follows:

Zenith Company Stock Fund	$	343,048
Mutual funds	2,449,463
Common collective trust funds	1,192,333
Pooled separate accounts	179,727
Total net appreciation in the fair value of investments	$	4,164,571

4.Nonparticipant-Directed Investments

As of December 31, 2006 and December 31, 2005, $2,702,463 and $3,524,060, respectively, of the net assets in the Zenith Company Stock Fund were nonparticipant-directed.

Information about the significant components of the changes in net assets available for plan benefits relating to the nonparticipant-directed investment in the Zenith Company Stock Fund for the year ended December 31, 2006 is as follows:

Additions:
Investment gain	$	75,699
Deductions:
Benefits paid to participants	(709,715		)
Transfers and fees	(187,581		)
Total deductions	(897,296		)
Net (decrease) increase	$	(821,597	)

As of January 1, 2007, the restriction on these funds was lifted and participants are able to divest all or any portion of such funds that were invested in Zenith stock and to reinvest an equivalent amount in other investment options offered by the Plan.

5.Risks and Uncertainties

The Plan provides for various investment options in any combination of mutual funds, cash, stock, group annuity contracts and other investment securities. Investment securities are exposed to various risks, such as interest rate, market and credit risk. Due to the level of risk associated with certain investment securities and the level of uncertainty related to changes

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in the value of investment securities, it is at least reasonably possible that changes in risks in the near term would materially affect participants’ account balances and the amounts reported in the Statements of Net Assets Available for Benefits and the Statement of Changes in Net Assets Available for Benefits.

If one or all of the unallocated, guaranteed investment contracts were to be terminated by the Plan prior to the final maturity date, and the Plan’s assets withdrawn, the amount received by the Plan could be less than the fair value under relevant provisions of the agreements.

6.Tax Status

The Plan received a determination letter from the Internal Revenue Service (“IRS”), dated November 16, 1998, which states that the Plan qualifies under Sections 401(a) and 401(k) of the Internal Revenue Code (the “Code”) and the Trust is exempt from federal income taxes under Section 501(a) of the Code. Plan amendments subsequent to the effective date of the IRS determination letter are not covered by the letter.

The Plan adopted a prototype plan document and its related opinion letter effective as of January 1, 2002, which stated that the prototype plan is designed in accordance with applicable sections of the Code. The Company believes that the Plan is designed and is being operated in compliance with the applicable requirements of the Code.

Subsequently, on January 31, 2007, The Company submitted an amended and restated Plan to the IRS and requested an updated determination letter. Issuance of an updated determination letter is pending.

7.Party-in-Interest

In 2006, The 401K Company acted as an agent for the Trustee and provided custodial and record keeping services to the Plan and, therefore, is a party-in-interest to the Plan. Payments for these services are statutorily exempt from the prohibited transaction rules of ERISA and the Code.

In 2005, certain Plan investments were in a mutual fund and two pooled separate accounts managed by MetLife. MetLife acted as agent for the Trustee and provided custodial and record keeping services to the Plan and, therefore, transactions in these investments are party-in-interest transactions.  However, they are statutorily exempt from the prohibited transaction rules of ERISA and the Code.

Transactions in Zenith National common stock, which is offered to participants as a Plan investment option, are party-in-interest transactions. However, such transactions are statutorily exempt from the prohibited transaction rules of ERISA and the Code.  For the

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year ended December 31, 2006, the Plan purchased $7,838,113 and sold $1,456,234 of Zenith National common stock.

Participant loans are party-in-interest transactions, for which a statutory exemption from the prohibited transaction rules of ERISA and the Code exists.

8.Reconciliation of Financial Statements to the Form 5500

Amounts allocated to withdrawing participants for benefit claims that have been processed and approved for payment prior to December 31, but not yet paid, are included in net assets available for benefits. For reporting to the Department of Labor, these amounts are reported as a liability on the Form 5500.

The following is a reconciliation of net assets available for benefits as of December 31, 2006 as shown in the accompanying financial statements to those shown in the Form 5500:

Net assets available for benefits per the accompanying financial statements	$	95,204,319
Amounts allocated to withdrawing participants at end of year	(33,901		)
Less: Adjustment from fair value to contract value for fully benefit-responsive investment contracts	(243,681		)
Net assets available for benefits per Form 5500	$	94,926,737

The following is a reconciliation of total income for the year ended December 31, 2006 as shown in the accompanying financial statements to those shown in the Form 5500:

Total income per the accompanying financial statements	$	14,644,047
Amounts allocated to withdrawing participants at end of year	(33,901		)
Less: Adjustment from fair value to contract value for fully benefit-responsive investment contracts	(243,681		)
Total income per Form 5500	$	14,366,465

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The Zenith 401(k) Plan
Schedule H, Line 4i - Schedule of Assets (Held at End of Year)
As of December 31, 2006
Employer Identification Number (EIN): 95-2702776
Plan Number (PN): 001
(See Report of Independent Registered Public Accounting Firm)

(a)	(b) Identity of Issue, Borrower, Lessor, or Similar Party	(c)   Description of Investments, Including Maturity Date, Rate of Interest, Collateral, Par or Maturity Value	(d) Cost			(e) Current Value
(1)	Zenith National Insurance Corp.	Common Stock, $1.00 par value per share		$	7,256,695		$	17,742,722
	Galliard	Galliard Customized Managed Stable Value Fund					20,388,597
	American Funds	EuroPacific Growth Fund R4/ Mutual Fund					13,166,996
	Hotchkis & Wiley	Hotchkis & Wiley Large Cap Value I/ Mutual Fund					12,048,759
	American Funds	Growth Fund of America R4/ Mutual Fund					8,556,862
	RS Partners	RS Partners Fund A/ Mutual Fund					5,554,389
	Vanguard	Vanguard Explorer/ Mutual Fund					5,063,522
	State Street	State Street S&P 500 Index L/ Collective Trust					4,773,229
	MFS	MFS Total Return A/ Mutual Fund					3,211,726
	American Funds	Bond Fund of America R4/ Mutual Fund					1,973,431
	Nationwide	Money Market Funds					1,836
(2)	Participant Loans	Various Maturity Dates — interest rate ranges from 4.0 - 9.50%					1,742,449
	Total investments						$	94,224,518

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Signature

Pursuant to the requirements of the Securities Exchange Act of 1934, the trustees (or other persons who administer the employee benefit plan) have duly caused this annual report to be signed on its behalf by the undersigned, thereunto duly authorized.

		THE ZENITH 401(k) PLAN
Date: June 28, 2007	By:	/s/ Kari Van Gundy
		Kari Van Gundy
		Chairperson of The Zenith 401(k) Plan
		Administrative Committee