EXHIBIT 5.1

                        Blank Rome Comisky & McCauley LLP
                                Counselors at Law
                                One Logan Square
                      Philadelphia, Pennsylvania 19103-6998
                                  215-569-5500
                                Fax 215-569-5555

                                  May 25, 2001

NCO Group, Inc.
515 Pennsylvania Avenue
Ft. Washington, Pennsylvania 19422

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

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
2,000,000 shares of common stock, no par value (the "Common Stock"), by the
Company pursuant to the 1996 Stock Option 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 Restated and Amended Articles of Incorporation and Bylaws,
(ii) resolutions adopted by the Board of Directors and shareholders of the
Company, (iii) the Registration Statement and (iv) the Plan as amended. 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
Registration Statement.

                                      Sincerely,


                                      /s/ BLANK ROME COMISKY & McCAULEY LLP