POWER OF ATTORNEY


KNOW ALL MEN BY THESE PRESENT, that the undersigned hereby constitutes and
appoints Ronald W. Rudolph and Joseph Peterson, M.D. as his/her true and
lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer and/or director of On Assignment, Inc. (the "Company"),
any and all Forms 3, 4 and 5 required to be filed by the undersigned in
accordance with Section 16(a) of the Securities Exchange Act of 1934 and
the rules thereunder;

(2) do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such Form 3,
4 or 5 and timely file such form with the United States Securities and
Exchange Commission and any stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit
to, in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of
the undersigned, pursuant to this Power of Attorney, shall be in such form
and shall contain such terms and conditions as such attorney-in-fact may
approve in his/her discretion.

The undersigned hereby grants to such attorney-in-fact full power and authority
to do and perform all and every act and thing whatsoever requisite, necessary,
and proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do if personally present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney-in-fact, or his/her substitute
or substitutes, shall lawfully do or cause to be done by virtue of this Power
of Attorney and the rights and powers herein granted.  The undersigned
acknowledges that no such attorney-in-fact, in serving in such capacity at the
request of the undersigned, is hereby assuming, nor is the Company hereby
assuming, any of the undersigned's responsibilities to comply with Section 16
of the Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to
the undersigned's holdings of and transactions in securities issued by the
Company, unless earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorney-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 10th day of May, 2004


Shawn Mohr