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                         NORTH AMERICAN SCIENTIFIC, INC.

                              AMENDED AND RESTATED
                             1996 STOCK OPTION PLAN

     1.   PURPOSE OF THE PLAN. Under this 1996 Stock Option Plan (the "Plan") of
North American Scientific, Inc. (the "Company") options may be granted to
eligible employees, directors and consultants to purchase shares of the
Company's capital stock. The Plan is designed to enable the Company to attract,
retain, and motivate its employees, directors and consultants by providing for
or increasing the proprietary interests of such individuals in the Company. The
Plan provides for options which qualify as incentive stock options ("Incentive
Options") under Section 422 of the Internal Revenue Code of 1986, as amended
(the "Code"), as well as options which do not so qualify ("Nonstatutory
Options"). Any option granted under this Plan shall be clearly identified as
either an Incentive Option or a Nonstatutory Option.

     2.   STOCK SUBJECT TO PLAN. The aggregate number of shares which may be
issued under options is 500,000 shares of the Company's Common Stock, $0.01 par
value ("Common Stock"), subject to the adjustments hereinafter provided. Such
number of shares shall be reserved by the Company for options granted under this
Plan. The shares which may be issued or delivered under the Plan may be either
authorized but unissued shares or treasury shares or partly each. Shares of
stock subject to the unexercised portions of any options granted under this Plan
which expire or terminate or are canceled may again be subject to options under
the Plan.

     3.   ELIGIBILITY. The employees eligible to be considered for the grant of
Incentive Options hereunder are all employees (including directors) regularly
employed by the Company. All such employees and all nonemployed directors or
consultants to the Company shall also be eligible to receive Nonstatutory
Options hereunder.

     4.   $100,000 INCENTIVE OPTION EXERCISE LIMITATION. The aggregate fair
market value of the stock for which Incentive Options granted to any one
eligible employee under this Plan and under all incentive stock option plans of
the Company, its parent(s) and any subsidiaries, may by their terms first become
exercisable during any calendar year shall not exceed $100,000, determining fair
market value of the stock subject to any option as of the time that option is
granted. If the date on which one or more Incentive Options could be first
exercised would be accelerated pursuant to any other provision of the Plan or
any stock option agreement referred to in Section 10, or an amendment thereto,
and the acceleration of such exercise date would result in a violation of the
restriction set forth in the preceding sentence, then notwithstanding any such
other provision the exercise date of such Incentive Options shall be accelerated
only to the extent, if any, that is permitted under Section 422 of the Code and
the exercise date of the Incentive Options with the lowest option prices shall
be accelerated first. Any exercise date which cannot be accelerated without
violating the $100,000
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restriction of this section shall nevertheless be accelerated, and the portion
of the option becoming exercisable thereby shall be treated as a nonstatutory
option.

     5.   OPTION PRICE. The purchase price at which each stock option may be
exercised (the "Option Price") shall be such price as the Board of Directors, in
its discretion, shall determine, and, in the case of Incentive Options, shall
not be less than one hundred percent (100%) of the fair market value per share
of the Common Stock covered by the Incentive Option on the date of grant, except
that in the case of an Incentive Option granted to an employee who, immediately
prior to such grant, owns stock possessing more than ten percent (10%) of the
total combined voting power of all classes of stock of the Company or any
subsidiary (a "Ten Percent Employee"), the Option Price shall not be less than
one hundred ten percent (110%) of such fair market value on the date of grant.
For purposes of this Section 5, the fair market value of the Common Stock shall
be determined as provided in Section 11. For purposes of this Section 5, an
individual (a) shall be considered as owning not only shares of the Common Stock
owned individually but also all shares that are at the time owned, directly or
indirectly, by or for the spouse, ancestors, lineal descendants and brothers and
sisters (whether by the whole or half blood) of such individual, and (b) shall
be considered as owning proportionately any shares owned, directly or indirectly
by or for any corporation, partnership, estate or trust in which such individual
shall be a shareholder, partner or beneficiary.

     6.   EXERCISE OF OPTION. The option agreement may provide for partial
exercise in installments. Exercisable options may be exercisable in full or in
part. The period of time in which an option may be exercised shall be the period
designated in the option. In the case of an Incentive Option such period shall
not exceed ten (10) years from the date the option is granted and with respect
to a Ten Percent Employee, such period of time shall not exceed five (5) years
from the date the Incentive Option is granted. No Nonstatutory Option shall be
exercisable after the expiration of ten years from the date of grant. An option
to the extent exercisable at any time may be exercised in whole or in part.

     7.   PAYMENT OF OPTION PRICE. Payment for stock purchased under any
exercise of an option granted under this Plan shall be made in full in cash
concurrently with such exercise. Alternatively, such payment may be made in
whole or in part with shares of the same class of stock as that then subject to
the option, delivered in lieu of cash concurrently with such exercise, the
shares so delivered to be valued on the basis of the fair market value of stock
(determined in a manner provided in Section 11 hereof) provided that the Company
is not then prohibited from purchasing or acquiring shares of such stock.

     Notwithstanding the foregoing, the Company shall not be obligated to accept
payment of the exercise price pursuant to this Section 7 unless the stock
tendered as payment for the exercise price has been held by the optionee for at
least six months. The Company also has the discretion to refuse any other method
of payment that would cause the Plan or the option agreements issued thereunder
to be treated for accounting purposes as creating stock appreciation rights or
other "variable stock plan" characteristics which would cause the Company to
recognize a charge to earnings.


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     8.   NONTRANSFERABILITY. Any option granted under this Plan shall by its
terms be nontransferable by the optionee other than by will or the laws of
descent and distribution and is exercisable during the optionee's lifetime only
by him or by his guardian or legal representative.

     9.   TERMINATION OF OPTION. In the case of Incentive Options:

          a.   If the employment or other service to the Company or a subsidiary
     of an optionee (whether employee, nonemployed director, or consultant) who
     is not disabled within the meaning of Section 422(c)(6) of the Code (a
     "Disabled Optionee") is terminated without cause, quits or retires under
     any retirement plan of the Company or a subsidiary, any then outstanding
     and exercisable stock option held by such an optionee shall be exercisable,
     in accordance with the provisions of the stock option agreement referred to
     in Section 10, by such optionee at any time prior to the expiration date of
     such stock option or within three months after the date of termination of
     employment or service, whichever is the shorter period;

          b.   If the employment of an optionee who is a Disabled Optionee is
     terminated without cause or if the service of a nonemployed director or
     consultant terminates because such individual becomes a Disabled Optionee,
     any then outstanding and exercisable stock option held by such an optionee
     shall be exercisable, in accordance with the provisions of the stock option
     agreement referred to in Section 10, by such an optionee at any time prior
     to the expiration date of such stock option or within one year after the
     date of such termination of employment or service, whichever is the shorter
     period;

          c.   Following the death of an optionee during employment or of a
     nonemployed director or consultant while serving as a director or
     consultant of the Company or a subsidiary, any outstanding and exercisable
     stock option held by such an optionee at the time of death shall be
     exercisable, in accordance with the provisions of the stock option
     agreement referred to in Section 10, by the person or persons entitled to
     do so under the will of the optionee, or, if the optionee shall fail to
     make testamentary disposition of the stock option or shall die intestate,
     by the legal representative of the optionee at any time prior to the
     expiration date of such stock option or within one year after the date of
     death, whichever is the shorter period.

     For all options issued hereunder, if the Company terminates the employment
of an optionee for cause, all outstanding stock options held by the optionee at
the time of such termination shall automatically terminate unless the Board of
Directors notifies the optionee that his options will not terminate. A
termination "for cause" shall be defined under each written option agreement
issued pursuant to Section 10.

     Whether termination of employment or other service is a termination "for
cause" and whether an optionee is disabled within the meaning of Section
422(c)(6) of the Code shall be determined in each case, in its discretion, by
the Board of Directors and any such determination by the Board of Directors
shall be final and binding.


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     10.  WRITTEN OPTION AGREEMENT. All options granted pursuant to the Plan
shall be evidenced by written option agreements. Such option agreements shall
comply with and be subject to all of the terms, conditions, and limitations set
forth in this Plan and such further provisions, not inconsistent with this Plan,
as the Board of Directors shall deem appropriate.

     11.  DETERMINATION OF FAIR MARKET VALUE. Fair market value of the Common
Stock shall be the closing price of the Common Stock on the Vancouver Stock
Exchange (or such successor exchange or automated quotation system upon which
the Common Stock becomes listed) on the day prior to the grant.

     12.  ADJUSTMENTS. If the outstanding shares of stock of the class then
subject to this Plan are increased or decreased, or are changed into or
exchanged for a different number or kind of shares or securities, as a result of
one or more reorganizations, recapitalization, stock splits, reverse stock
splits, stock dividends or the like, appropriate adjustments shall be made in
the number and/or kind of shares or securities for which options may thereafter
be granted under this Plan and for which options then outstanding under this
Plan may thereafter be exercised. The Board of Directors shall make such
adjustments as it may deem fair, just and equitable to prevent substantial
dilution or enlargement of the rights granted to or available for optionees. No
adjustment provided for in this Section 12 shall require the Company to issue or
sell a fraction of a share or other security.

     If any such adjustment provided for in this Section 12 requires the
approval of stockholders in order to enable the Company to grant Incentive
Options, then no such adjustment shall be made without the required stockholder
approval. Notwithstanding the foregoing, in the case of Incentive Options, if
the effect of any such adjustment would be to cause the stock option to fail to
continue to qualify as an Incentive Option or to cause a modification, extension
or renewal of such stock option within the meaning of Section 424 of the Code,
the Board of Directors may elect that such adjustment not be made but rather
shall use reasonable efforts to effect such other adjustment of each then
outstanding stock option as the Board of Directors, in its sole discretion,
shall deem equitable and which will not result in any disqualification,
modification, extension or renewal (within the meaning of Section 424 of the
Code) of such Incentive Option.

     13.  ADMINISTRATION. The Plan shall be administered by the Board of
Directors. The Board of Directors may interpret the Plan, prescribe, amend and
rescind any rules or regulations necessary or appropriate for the administration
of the Plan, and make all determinations, in its discretion, as to which
eligible employees will receive options, the number of shares subject to the
options and the exercise price. In addition, the Board of Directors may make
such other determinations and take such other action it deems necessary or
advisable. Without limiting the generality of the foregoing, the Board of
Directors may, in its discretion, treat all or any portion of any period during
which a participant is on military or other approved leave of absence from the
Company or a subsidiary as a period of employment of such participant by the
Company or such subsidiary, as the case may be, for purposes of accrual of his
rights under his awards; provided, however, that no Incentive Option may be
awarded to an employee while he is on leave of absence.


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     14.  LIMITATIONS RESPECTING INCENTIVE OPTIONS. It is the intent of the
Company to conform strictly to the requirements of Code Section 422 with regard
to Incentive Options granted pursuant to this Plan. Therefore, notwithstanding
any other provision of this Plan, nothing herein with regard to Incentive
Options shall contravene any requirement set forth in Code Section 422 and if
inconsistent provisions are otherwise found herein, they shall be deemed void
and unenforceable or automatically amended to conform, as the case may be.

     15.  RIGHTS AS A STOCKHOLDER. An optionee, or his executor, administrator
or legatee if he be deceased, shall have no rights as a stockholder with respect
to any stock covered by his option under the date of issuance of the stock
certificate to him or such stock after receipt of the consideration in full set
forth in the option agreement or as may be approved by the Board of Directors.
Except as provided in Section 12 hereof, no adjustments shall be made for
dividends, whether ordinary or extraordinary, whether in cash, securities, or
other property, for distributions in which the record date is prior to the date
for which the stock certificate is issued.

     16.  MODIFICATION. EXTENSION AND RENEWAL. Subject to the conditions of, and
within the limitations prescribed in, Section 14, hereof, the Board of Directors
may modify, extend or renew options which are outstanding as granted under the
Plan if otherwise consistent herewith. Notwithstanding the foregoing, no
modification shall, without the prior written consent of the optionee, alter,
impair or waive any rights or obligations of any option theretofore granted
under the Plan.

     17.  INVESTMENT PURPOSES, ETC. Prior to the issuance or delivery of any
shares of the common stock under the Plan, the person exercising the stock
option may be required to (a) represent and warrant that the shares of the
Common Stock to be acquired upon exercise of the stock option are being acquired
for investment for the account of such person and not with a view to resale or
other distribution thereof, (b) represent and warrant that such person will not,
directly or indirectly, transfer, sell, assign, pledge, hypothecate or otherwise
dispose of any such shares unless the transfer, sale, assignment, pledge,
hypothecation or other disposition of the shares is pursuant to effective
registrations under the 1933 Act and applicable state or foreign securities laws
or pursuant to appropriate exemptions from any such registrations, (c) execute
such further documents as may be reasonably required by the Board of Directors
upon exercise of the option or any part thereof, including but not limited to
stock transfer restrictions. The certificate or certificates representing the
shares of the common stock to be issued or delivered upon exercise of a stock
option may bear a legend evidencing the foregoing and other legends required by
any applicable securities laws. Furthermore, nothing herein or any option
granted hereunder shall require the Company or any subsidiary to issue any stock
upon exercise of any option if the issuance would, in the opinion of counsel for
the Company, constitute a violation of the Securities Act of 1933, as amended,
the California securities laws, or any other applicable rule or regulation then
in effect.

     18.  NO RIGHT TO CONTINUED EMPLOYMENT. This Plan, and any option granted
under this Plan, shall not confer upon any optionee any right with respect to
continued employment by or service to the Company or any subsidiary, nor shall
they alter, modify, limit or interfere with any right or privilege of the
Company or any subsidiary under any employment or service contract heretofore or


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hereinafter executed with any optionee, including the right to terminate any
optionee's employment, directorship, or consultancy service, at any time for or
without cause.

     19.  DISPOSITION OF INCENTIVE OPTION SHARES. Except (a) as provided in
options to the Company and other holders of the stock contained in stock
transfer restriction agreements to which the Company is a party, or (b) in
connection with reorganizations or other transactions described in Section 12
hereof, no stock acquired by the exercise of an Incentive Option granted under
the Plan shall be transferable, otherwise than by will or the laws of descent
and distribution, within two (2) years after the date the option was granted or
within one (1) year after the transfer of such share of stock to the optionee
pursuant to the exercise of the option. Each certificate representing the
acquired shares shall bear a legend to this effect.

     20.  COMPLIANCE WITH OTHER LAWS AND REGULATIONS. The Plan, the options
granted hereunder and the obligation of the Company to sell and deliver stock
under such options, shall be subject to all applicable federal and state laws,
rules, regulations and to such approvals by any government or regulatory
authority or investigative agency as may be required. The Company shall not be
required to issue or deliver any certificates for shares of stock prior to (a)
the listing of any such stock to be acquired pursuant to the exercise of any
option on any stock exchange on which the stock may then be listed, and (b) the
compliance with any registration requirements or qualification of such shares
under any federal or state securities laws, or obtaining any ruling or waiver
from any government body which the Company or it subsidiaries shall, in their
sole discretion, determine to be necessary or advisable, or which, in the
opinion of counsel to the Company or its subsidiaries, is otherwise required.

     21.  CORPORATE REORGANIZATIONS. Upon the dissolution or liquidation of the
Company, or upon a reorganization, merger or consolidation of the Company as a
result of which the outstanding securities of the class then subject to options
hereunder are changed into or exchanged for cash or property or securities not
of the Company's issue, or upon a sale of substantially all the property of the
Company to, or the acquisition of stock representing more than eighty percent
(80%) of the voting power of the stock of the Company then outstanding by
another corporation or person, the Plan shall terminate, and all options
theretofore granted hereunder shall terminate, unless provision be made in
writing in connection with such transaction for the continuance of the Plan
and/or for the assumption of options theretofore granted, or the substitution
for such options of options covering the stock of a successor employer
corporation, or a parent or a subsidiary thereof, with appropriate adjustments
as to the number and kind of shares and prices, in which event the Plan and
options theretofore granted shall continue in the manner and under the terms so
provided. If the Plan and unexercised options shall terminate pursuant to the
foregoing sentence, all persons entitled to exercise any unexercised portions of
options then outstanding shall have the right, at such time prior to the
consummation of the transaction causing such termination as the Company shall
designate, to exercise the unexercised portions of their options, including the
portions thereof which would, but for this Section 21, not yet be exercisable.


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     22.  WITHHOLDING. If, upon exercise of any Nonstatutory Option (or any
Incentive Option which is treated as a Nonstatutory Option because it fails to
meet the requirements set forth herein for Incentive Options), the optionee
fails to tender payment to the Company for any federal income tax withholding,
the Board of Directors shall withhold from the optionee sufficient shares or
fractional shares having a fair market value (determined under Section 11) equal
to any amount which the Company is required to withhold under the Code.

     23.  AMENDMENT AND TERMINATION. The Company may alter, amend, suspend or
terminate this Plan, provided that no such action shall deprive an optionee,
without his consent, of any option granted to the optionee pursuant to this Plan
or of any of such optionee's rights under such option. Except as herein provided
no such action of the Company, unless approved by the shareholders of the
Company within twelve months prior or twelve months after such action, may:

          a. increase the maximum number of shares for which options granted
     under this plan may be exercised;

          b. reduce the minimum permissible exercise price;

          c. extend the ten-year duration of this Plan set forth herein; or

          d. alter the class of employees eligible to receive options under the
     Plan.

     24.  PLAN DATE AND DURATION. The Plan shall take effect on the date it is
adopted by the Board of Directors of the Company. Options may not be granted
under this Plan more than ten years after the date of the adoption of this Plan,
or of shareholder approval thereof, whichever is earlier.


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