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                                                                     EXHIBIT 5.1

                          [Baker & McKenzie Letterhead]


                                December 2, 1999

Interim Services Inc.
2050 Spectrum Boulevard
Fort Lauderdale, Florida 33309-3799

         Re:  Registration Statement on Form S-8

Ladies and Gentlemen:

     On the date hereof, Interim Services Inc., a Delaware corporation (the
"Company"), sent for filing with the Securities and Exchange Commission a
Registration Statement on Form S-8 (the "Registration Statement"), under the
Securities Act of 1933, as amended (the "Act"). The Registration Statement
relates to the offering and sale by the Company of up to 2,200,000 shares of the
Company's Common Stock, par value $.01 per share (the "Common Stock"), pursuant
to stock options ("Options") granted or to be granted under the Company's
Amended and Restated 1998 Stock Incentive Plan (the "Plan"). We have acted as
counsel to the Company in connection with the preparation and filing of the
Registration Statement.

         In connection therewith, we have examined and relied upon the original
or a copy, certified to our satisfaction, of (i) the Amended and Restated
Certificate of Incorporation and Bylaws of the Company; (ii) records of
corporate proceedings of the Company authorizing the Plan and preparation of the
Registration Statement and related matters; (iii) the Registration Statement and
exhibits thereto; and (iv) such other documents and instruments as we have
deemed necessary for the expression of the opinions herein contained. In making
the foregoing examinations, we have assumed the genuineness of all signatures
and the authenticity of all documents submitted to us as originals, and the
conformity to original documents of all documents submitted to us as certified
or photostatic copies. As to various questions of fact material to this opinion,
we have relied, to the extent we deem reasonably appropriate, upon
representations or certificates of officers or directors of the Company and upon
documents, records and instruments furnished to us by the Company, without
independently checking or verifying the accuracy of such documents, records and
instruments.

         Based upon the foregoing examination, we are of the opinion that the
Company presently has available at least 2,200,000 shares of authorized and
unissued Common Stock from which the 2,200,000 shares of Common Stock proposed
to be sold pursuant to the exercise of Options granted under the Plan may be
issued. In addition, assuming that the Company maintains an adequate number of
authorized but unissued shares of Common Stock available for issuance to those
persons who choose to exercise their Options, and that the consideration for the
underlying shares of Common Stock issued pursuant to the Options is actually
received by the Company as provided in the Plan, we are of the opinion that the
shares of Common Stock issued pursuant to the exercise of Options granted under
and in accordance with the terms of the Plan will be duly and validly issued,
fully paid and nonassessable.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In giving such consent, we do not admit that we come
within the category of persons whose consent is required by Section 7 of the Act
or the rules and regulations of the Commission thereunder.

                                                   Sincerely,


                                                   /s/ BAKER & McKENZIE