EXHIBIT 5.1

                  Opinion of Blank Rome Comisky & McCauley LLP

                               September 21, 1999

NCO Group, Inc.
515 Pennsylvania Avenue
Fort Washington, PA 19034

         Re: NCO Group, Inc. Registration Statement on Form S-8
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Gentlemen:

         We have acted as counsel to NCO Group, Inc. (the "Company") in
connection with the Registration Statement on Form S-8 (the "Registration
Statement") filed by the Company with the Securities and Exchange Commission
pursuant to the Securities Act of 1933, as amended, relating to the offer and
sale of up to 215,841 shares of common stock, no par value (the "Common Stock"),
by the Company pursuant to the Compass International Services Corporation
Employee Incentive Compensation Plan (the "Plan"). This opinion is furnished
pursuant to the requirements of Item 601(b)(5) of Regulation S-K.

         In rendering this opinion, we have examined only the following
documents: (i) the Company's Amended and Restated Articles of Incorporation and
Bylaws, (ii) resolutions adopted by the Board of Directors of the Company, (iii)
the Registration Statement and (iv) the Plan. We have not performed any
independent investigation other than the document examination described. Our
opinion is therefore qualified in all respects by the scope of that document
examination. We have assumed and relied, as to questions of fact and mixed
questions of law and fact, on the truth, completeness, authenticity and due
authorization of all certificates, documents, and records examined and the
genuineness of all signatures. This opinion is limited to the laws of the
Commonwealth of Pennsylvania.

         Based upon and subject to the foregoing, we are of the opinion that the
shares of Common Stock of the Company which are being offered and sold by the
Company pursuant to the Registration Statement and the Plan, when sold in the
manner and for the consideration contemplated by the Registration Statement and
the Plan, will be legally issued, fully paid and non-assessable.

         We hereby consent to the filing of this opinion as an Exhibit to the
Registrant Statement.

                       Sincerely,



                       /s/ BLANK ROME COMISKY & McCAULEY LLP