S-8

Registration No. 333-            

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ZENITH NATIONAL INSURANCE CORP.

(Exact Name of Registrant as Specified in Its Charter)

Delaware	95-2702776
State or Other Jurisdiction of Incorporation or Organization)	(IRS Employer Identification No.)

21255 Califa Street

Woodland Hills, California 91367

(Address of Principal Executive Offices) (Zip Code)

Zenith National Insurance Corp. 2007 Employee Stock Purchase Plan

(Full Title of the Plan)

Michael E. Jansen

Zenith National Insurance Corp.

21255 Califa Street

Woodland Hills, California 91367

(Name and Address Of Agent For Service)

(818) 713-1000

(Telephone Number, Including Area Code, Of Agent For Service)

CALCULATION OF REGISTRATION FEE

Title of Securities to be Registered	Amount to be Registered	Proposed Maximum Offering Price Per Unit(1)	Proposed Maximum Aggregate Offering Price(1)	Amount of Registration Fee(1)
Common Stock, par value $1.00 per share	500,000	$48.52	$24,260,000	$744.78

(1)Estimated solely for purposes of calculating the registration fee pursuant to Rules 457(c) and (h) under the Securities Act of 1933, as amended, on the basis of the average of the high ($48.80) and low ($48.23) sale prices for a share of common stock, par value $1 per share, of Zenith National Insurance Corp. (“Common Stock”) on the New York Stock Exchange on June 4, 2007. The Registration Fee was calculated based on $30.70 per $1 million of Agggregate Offering Price in accordance with the current Securities and Exchange Commission Fee Schedule.

PART I

INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1. Plan Information.*

Item 2. Registrant Information and Employee Plan Annual Information.*

* The document(s) containing the information specified in Part I of Form S-8 have been or will be sent or given to participants as specified by Rule 428(b)(1) under the Securities Act of 1933, as amended (the “Securities Act”).

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

Zenith National Insurance Corp. (“Zenith”) hereby incorporates by reference into this registration statement the following documents filed with the Securities and Exchange Commission (the “Commission”):

A)  Current Report on Form 8-K filed February 16, 2007;

B)  Annual Report on Form 10-K for the year ended December 31, 2006 filed February 16, 2007;

C)  Definitive Proxy Statement for the 2007 Annual Meeting of Stockholders filed April 5, 2007;

D)  Quarterly Report on Form 10-Q for the quarter ended March 31, 2007 filed April 23, 2007;

E)  Current Report on Form 8-K filed May 24, 2007; and

F)  The description of the Common Stock which is contained in Zenith’s Registration Statement on Form 8-A filed with the Commission pursuant to Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) on July 15, 1987, which incorporates such description from Zenith’s Registration Statement No. 33-1431 filed with the Commission pursuant to the Securities Act on November 8, 1985, as amended by Amendment No. 1 thereto filed with the Commission on November 21, 1985.

All documents subsequently filed by Zenith pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act (other than current reports furnished on Form 8-K), prior to the filing of a post-effective amendment which indicates that all securities registered hereby have been sold or which deregisters all securities then remaining unsold, shall be deemed incorporated by reference herein and to be a part hereof from the date of the filing of such documents. Any statement contained herein or in a document incorporated or deemed to be incorporated by reference herein will be deemed to be modified or superseded for purposes of this registration statement to the extent a statement contained herein or in any other subsequently filed document that is or is deemed to be incorporated by reference herein modifies or supersedes such previous statement.  Any such statement so modified or superseded will not be deemed to constitute a part of this registration statement, except as so modified or superseded.

2

Item 4.Description of Securities.

Not applicable.

Item 5.Interests of Named Experts and Counsel.

Not applicable.

Item 6.Indemnification of Directors and Officers.

Section 145 of the Delaware General Corporation Law authorizes a corporation, subject to the procedures and limitations stated therein, to indemnify its directors, officers, employees and agents against expenses, including attorneys’ fees, judgments, fines and amounts paid in settlement reasonably incurred, including liabilities under the Securities Act, provided they act in good faith and in a manner reasonably believed to be in or not opposed to the best interests of the corporation, although in the case of proceedings brought by or on behalf of the corporation, indemnification is limited to expenses and is not permitted if the individual is adjudged liable to the corporation, unless the court determines otherwise.   The statute provides that indemnification pursuant to its provisions is not exclusive of other rights of indemnification to which a person may be entitled under any by-law, agreement, vote of stockholders or disinterested directors or otherwise.  Zenith’s certificate of incorporation and by-laws provide for indemnification of its officers and directors to the fullest extent permitted by Delaware law.

Section 145 of the Delaware General Corporation Law also authorizes a corporation to purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation against any liability asserted against him or her and incurred by him or her in his or her capacity as a director, officer, employee or agent of the corporation, or arising out of his or her status as a director, officer, employee or agent of the corporation.  Zenith maintains liability insurance covering its directors and officers for claims asserted against them or incurred by them in their capacity as directors and officers, including claims brought under the Securities Act, within the limits and subject to the limitations of the policies

Item 7.Exemption from Registration Claimed.

Not Applicable.

Item 8.Exhibits.

Exhibit No.	Description
4.1	Zenith National Insurance Corp. 2007 Employee Stock Purchase Plan
23.1	Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm
24.1	Power of Attorney (included on the signature page of the Registration Statement)

3

Item 9.Undertakings.

(A)The undersigned registrant hereby undertakes:

(1)To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i)To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii)To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement.  Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii)To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

(2)That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(B)That, for the purpose of determining liability of the Registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities:

The Registrant undertakes that in a primary offering of securities of the Registrant pursuant to this Registration Statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the Registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

4

(i)any preliminary prospectus or prospectus of the Registrant relating to the offering required to be filed pursuant to Rule 424 pursuant to the Securities Act of 1933;

(ii)any free writing prospectus relating to the offering prepared by or on behalf of the Registrant or used or referred to by the Registrant;

(iii)the portion of any other free writing prospectus relating to the offering containing material information about the Registrant or its securities provided by or on behalf of the Registrant; and

(iv)any other communication that is an offer in the offering made by the Registrant to the purchaser.

(C)The undersigned registrant hereby undertakes that, for purposes of determining liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(D)Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable.  In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer, or controlling person of the Registrant in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

5

SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Woodland Hills, State of California, on this 5th day of June, 2007.

ZENITH NATIONAL INSURANCE CORP.
By:		/s/ Stanley R. Zax
		Stanley R. Zax
	Chairman of the Board and President

6

POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Stanley R. Zax his or her true and lawful attorney-in-fact and agent with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any or all amendments (including post-effective amendments) to this Registration Statement, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this Registration Statement has been signed by the following persons in the capacities indicated, on June 5, 2007.

/s/ Stanley R.Zax	Chairman of the Board, President and
Stanley R. Zax	Director (Principal Executive Officer)
/s/ Kari L. Van Gundy	Senior Vice President and Chief Financial
Kari L. Van Gundy	Officer (Principal Accounting Officer)
/s/ Max M. Kampelman	Director
Max M. Kampelman
/s/ Robert J. Miller	Director
Robert J. Miller

7

/s/ Leon E. Panetta	Director
Leon E. Panetta
/s/ Catherine B. Reynolds	Director
Catherine B. Reynolds
/s/ Alan I. Rothenberg	Director
Alan I. Rothenberg
/s/ William S. Sessions	Director
William S. Sessions
/s/ Gerald Tsai, Jr.	Director
Gerald Tsai, Jr.
/s/ Michael Wm. Zavis	Director
Michael Wm. Zavis

8

EXHIBIT INDEX

Exhibit No.	Description
4.1	Zenith National Insurance Corp. 2007 Employee Stock Purchase Plan
23.1	Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm
24.1	Power of Attorney (included on the signature page of the Registration Statement)

9

EX-4.1

Exhibit 4.1

ZENITH NATIONAL INSURANCE CORP.

2007 EMPLOYEE STOCK PURCHASE PLAN

1.Purpose

The purpose of the 2007 Employee Stock Purchase Plan (“Plan”) is to attract and retain employees of outstanding ability and to motivate them to dedicate their maximum productive efforts to Zenith National Insurance Corp. (“Zenith”) and its direct and indirect subsidiaries. It is contemplated that only some of Zenith’s subsidiaries will adopt the Plan and Zenith and such adopting subsidiaries are herein referred to collectively as the “Companies” or individually as the “Company.” Under the Plan, certain employees of the Companies are able to purchase conveniently and systematically Zenith’s common stock, par value $1.00 per share (“Common Stock”), through payroll deductions supplemented by contributions by the Companies.

2.Definitions

For the purposes of this Plan:

(a)“Employee” means any person over 18 years of age who is carried on the payroll of a Company, as a full-time employee.

(b)“Administrator” means the person(s) or entity designated by Zenith’s Board of Directors to organize, oversee, run and otherwise administer the Plan. The Administrator, in its sole discretion, may engage others to perform certain of its administrative and recordkeeping functions.

(c)“Participant” means any Employee who files a written application in compliance with Section 4(a) hereof.

(d)“Payroll Period” means the period from the date on which the Employee customarily receives payment of regular salary or wages to the next successive date on which the Employee customarily receives such payment.

(e)“Brokerage Firm” means any business enterprise which is lawfully entitled to deal in securities on the over-the-counter exchange and derives a substantial portion of its revenues from dealing in securities on major national exchanges.

(f)“Street Account” means an account at a Brokerage Firm that is held for the benefit of all of the Participants in which the Common Stock purchased under this Plan is maintained. The Administrator shall cause records to be kept, in which each individual Participant’s interest in the Street Account is allocated to him or her.

3.Eligibility

Every Employee of the Companies shall be eligible to participate in the Plan.

4.Participation; Payroll Deductions

(a)Each eligible Employee may become a Participant in the Plan by filing a written application on such form as may be prescribed by the Administrator with the respective Company’s payroll office. Each application of an Employee shall become effective for the first Payroll Period beginning in the calendar month next succeeding the date on which such application is received.

(b)The Participant’s application shall specify the amount (the “Payroll Deduction Amount”) the Participant elects to contribute to the Plan for each Payroll Period and shall authorize the respective Company to withhold such amount from the salary or wages of such Participant with respect to each Payroll Period thereafter until such Participant’s participation in the Plan is terminated or until the amount of such deductions shall be changed or suspended as hereinafter provided. Notwithstanding anything to the contrary contained herein, no more than an amount equal to twenty-five percent (25%) of a Participant’s pre-tax salary or wages may be contributed to the Plan on an annual calendar year basis.

(c)A Participant’s application may be amended, by the Participant, to increase or decrease or to suspend the Payroll Deduction Amount; provided, however, that (i) the Payroll Deduction Amount may be increased only once, decreased only once and suspended only once in any calendar year and (ii) any suspension must be for a period of not less than four (4) months and shall continue until the Participant has notified the respective Company to recommence payroll deductions. Each such amendment and notice shall be made by filing a form prescribed by the Administrator with the respective Company’s payroll offices and shall become effective for the first Payroll Period beginning in the calendar month next succeeding the date on which such form is properly filed.

5.Establishment of Street Account and Purchases

The Administrator shall obtain, on an appropriate form, permission from each Participant to direct the Brokerage Firm to purchase Common Stock from time to time to be deposited in the Street Account pursuant to the Administrator’s directions.

6.Contributions by the Companies

Subject to an overall limit each calendar year of one (1) million dollars applicable to all such total contributions by the Companies, each Company shall contribute on behalf of each Participant employed by it an amount (the “Company Matching Amount”) equal to twenty-five percent (25%) of such Participant’s Payroll Deduction Amount. Upon reaching the overall calendar year limit of one (1) million dollars, no further Company Matching Amount shall be made to any Participant under the Plan for the remainder of the applicable calendar year.

7.Transmittal

Pursuant to the Plan, each Company shall accumulate on a monthly basis and hold, without interest, the Payroll Deduction Amounts for each Participant employed by it. All such amounts shall be delivered to the Administrator (to be applied in accordance with the provisions of this Plan) as promptly as possible after the close of the calendar month of withholding. Such delivery shall be accompanied by a transmittal listing the name and Payroll Deduction Amount and the corresponding Company Matching Amount for each Participant. Each Company’s Matching Amount shall be delivered to the Administrator concurrently with such transmittal.

8.Administration

Upon receipt of the amounts and transmittal set out in Section 7, the Administrator shall forward all of the Payroll Deduction Amounts and the corresponding Company Matching Amounts to the Brokerage Firm and shall direct the Brokerage Firm to purchase for each Participant as many shares of Common Stock as such Participant’s Payroll Deduction Amount and corresponding Company Matching Amount will permit and to deposit such Common Stock into the Street Account.

All commissions and fees incurred as a result of the Administrator’s directions to purchase Common Stock for a Participant shall be borne by the Company employing such Participant.

9.Confirmations

The Administrator shall forward to each Participant promptly after each purchase is made pursuant to Section 8 hereof a confirmation statement indicating the number of shares of Common Stock then acquired under the provisions of the Plan for the Participant, the cost thereof, the dates of acquisition, and the total number of shares credited to the Participant under the Plan.

10.Participants’ Sale of Common Stock

A Participant may at any time sell any or all of the Common Stock held for his or her benefit in the Street Account.

A partial or total withdrawal or sale of the Common Stock allocated to a Participant in the Street Account shall have no effect on the Participant’s payroll deductions and shall not effect a termination of the Participant’s participation in the Plan.

11.Termination of Participation

If a Participant shall die, retire, be totally and permanently disabled or cease to be continuously employed by any Company, such Participant’s participation in the Plan shall thereupon automatically terminate and the respective Company shall notify the Administrator of such termination in writing. The Administrator shall, as soon as is practicable, distribute to the Participant or his or her legal representative, the number of shares in the Street Account allocated to such Participant. Fractional shares shall be distributed in cash.

A Participant may also completely withdraw from the Plan by so declaring on a form to be supplied by the Administrator. In such event, the Administrator shall, as soon as practicable, distribute to the Participant the number of shares in the Street Account allocated to him or her. Fractional shares shall be distributed in cash.

Upon termination of participation or withdrawal from the Plan, Payroll Deduction Amounts withheld from the Participant’s salary or wages not yet delivered to the Administrator pursuant to Section 7 will be returned to him or her or, in the case of death, to his or her estate, without interest or any Company Matching Amount in connection therewith.

12.Voting and Other Rights

Except as otherwise provided herein, all rights of a holder of Common Stock shall vest in a Participant with respect to the Common Stock standing in the Street Account on such Participant’s behalf.

13.Transfer of Rights and Common Stock

Unless applicable state or federal law requires a contrary result:

(a)A Participant in the Plan may not assign, transfer, hypothecate, encumber, commute or anticipate an interest in the Plan, in any cash amount held by the Companies, the Administrator or Brokerage Firm pursuant to the Plan on behalf of each Participant for the purchase of Common Stock or in any Common Stock that may be held in the Street Account on the Participant’s behalf;

(b)Neither the interest of a Participant in the Plan nor in any cash amount held by the Companies, the Administrator or Brokerage Firm pursuant to the Plan on behalf of each Participant for the purchase of Common Stock nor in any Common Stock that may be held in the Street Account on the Participant’s behalf shall in any way be subject to any legal process or be levied upon or attached for payment of any claim against the Participant; and

(c)Any such attempted assignment, transfer, hypothecation, encumbrance, commutation or anticipation and any such attempted levy, attachment or other subjection to legal process shall be void and shall not be recognized by the Administrator, the Companies or the Brokerage Firm, as applicable.

14.Withholding on Company Matching Amounts

All Company Matching Amounts shall be treated as “wages” for services rendered by the Participant and will be subject to withholding for income and employment taxes.

15.Amendment, Suspension and Termination of the Plan

The Plan shall automatically terminate on June 30, 2013 unless terminated prior to that date pursuant to this Section.

Zenith’s Board of Directors may from time to time amend, suspend or terminate in whole or in part, and if terminated may reinstate, any or all of the provisions of the Plan, except that no amendment, suspension or termination may be made which, in the judgment of such Board of Directors, will retroactively affect adversely the rights of any Participant in the Plan without the prior written consent of such Participant.

The Plan may be suspended or terminated only upon ten (10) days’ prior written notice to the Administrator. In the event of suspension or termination of the Plan:

(a)Each Company shall deliver to the Administrator all Payroll Deduction Amounts and Company Matching Amounts. Such delivery shall be accompanied by a transmittal listing the names of Participants and Payroll Deduction Amounts and Company Matching Amounts corresponding to each Participant.

(b)On the business day preceding the effective date of termination or suspension of the Plan, the Administrator shall direct the Brokerage Firm to purchase for each Participant as many shares of Common Stock as the amount of cash, if any, then held for each Participant pursuant to the Plan will permit and to deposit such Common Stock into the Street Account.

(c)The Administrator shall, as soon as is practicable following suspension or termination of the Plan, distribute to each Participant or his or her legal representative the number of shares of Common Stock in the Street Account allocated to such Participant.

16.Interpretation

The Board of Directors of Zenith shall have full power and authority to interpret and construe any and all provisions of this Plan finally and conclusively as to all persons and entities having an interest thereunder, to adopt rules and regulations not inconsistent with the Plan for carrying out the Plan or for providing for matters not specifically covered in the Plan and to alter, amend and revoke any rules or regulations so adopted.

17.Administrator

The Administrator shall be appointed by Zenith’s Board of Directors to administer the Plan and may be discharged at any time in the sole discretion of such Board of Directors. Consequently, nothing in the Plan shall be deemed to create any obligation on the part of Zenith or the Administrator that the Administrator shall continue to administer the Plan. In the event that the Administrator shall cease to administer the Plan, Zenith may appoint any other person(s) or entity to administer the Plan.

18.Adoption

This Plan may be adopted by any direct or indirect subsidiary of Zenith through action of the Board of Directors of such subsidiary.

19.Brokerage Firm

The Brokerage Firm shall be engaged by the Zenith’s management and such engagement may be terminated at any time in the sole discretion of such Board of Directors. Consequently, nothing in the Plan shall be deemed to create any obligation on the part of Zenith or the Brokerage Firm that the Brokerage Firm shall continue to serve as Brokerage Firm under the Plan. In the event that the Brokerage Firm is terminated, Zenith’s management may engage any other Brokerage Firm to serve under the Plan.

EX-23.1

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form  S-8 of our report dated February 16, 2007 relating to the consolidated financial statements, management’s assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting, which appears in the 2006 Annual Report to Stockholders, which is incorporated by reference in Zenith National Insurance Corp.’s Annual Report on Form 10-K for the year ended December 31, 2006. We also consent to the incorporation by reference of our report dated February 16, 2007 relating to the financial statement schedules, which appears in such Annual Report on Form 10-K.

PricewaterhouseCoopers LLP

Los Angeles, California

June 5, 2007