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                                                                     Exhibit 5.1


                           Kirkpatrick & Lockhart LLP
                            Henry W. Oliver Building
                              535 Smithfield Street
                              Pittsburgh, PA 15222


                               September 27, 2001


WESCO International, Inc.
WESCO Distribution, Inc.
Commerce Court
Four Station Square, Suite 700
Pittsburgh, Pennsylvania, 15219

Ladies and Gentlemen:

         We have acted as counsel to WESCO Distribution, Inc., a Delaware
corporation (the "Company") and WESCO International, Inc., a Delaware
corporation ("Holdings"), in connection with the Registration Statement on Form
S-4 (the "Registration Statement") filed by Holdings and the Company with the
Securities and Exchange Commission under the Securities Act of 1933, as amended
(the "Securities Act"), relating to the registration by the Company of
$100,000,000 aggregate principal amount of its 9-1/8% Senior Subordinated Notes
due 2008 (the "Exchange Notes") and by Holdings of its guarantee of the
Company's obligations under the Exchange Notes (the "Guarantee"). The Exchange
Notes are proposed to be issued in accordance with the provisions of the
indenture (the "Indenture"), dated as of August 23, 2001, among the Company,
Holdings and Bank One, N.A., as Trustee.

         In connection with rendering the opinions set forth below, we have
examined the Registration Statement, the Prospectus contained therein, the
Indenture, which is filed as an exhibit to the Registration Statement, the
Certificate of Incorporation and By-laws of the Company and Holdings and
resolutions adopted by the Boards of Directors of the Company and Holdings on
July 25, 2001, and we have made such other investigation as we have deemed
appropriate. We have examined and relied on certificates of public officials. We
have not independently established any of the facts so relied on.

         For the purposes of this opinion letter we have made the assumptions
that are customary in opinion letters of this kind, including the assumptions
that each document submitted to us is accurate and complete, that each such
document that is an original is authentic, that each such document that is a
copy conforms to an authentic original, and that all signatures (other than
signatures on behalf of the Company) on each such document are genuine. We have
further assumed the legal capacity of natural persons, and we have assumed that
each party to the documents we have examined or relied on (other than the
Company and Holdings) has the legal capacity or authority and has satisfied all
legal requirements that are applicable to that party to

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WESCO International, Inc.
WESCO Distribution, Inc.
September 27, 2001
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the extent necessary to make such documents enforceable against that party. We
have not verified any of those assumptions.

         We are opining herein as to the effect of the laws of the State of New
York (excluding conflict of laws rules) and the General Corporation Law of the
State of Delaware. We are not opining on, and we assume no responsibility for,
the applicability to or effect on any of the matters covered herein of any other
laws, the laws of any other jurisdiction, or the local laws of any jurisdiction.

         Based on the foregoing, and subject to the foregoing and the additional
qualifications and other matters set forth below, it is our opinion that the
Exchange Notes and the Guarantee, when (a) the Company's outstanding 9 1/8%
Senior Subordinated Notes Due 2008, Issued 2001 have been exchanged in the
manner described in the Registration Statement, (b) the Exchange Notes have been
duly executed, authenticated, issued and delivered in accordance with the terms
of the Indenture, (c) the Indenture has been duly qualified under the Trust
Indenture Act of 1939, as amended, and (d) applicable provisions of "blue sky"
laws have been complied with, will constitute valid and binding obligations of
the Company and Holdings, as applicable, enforceable against the Company and
Holdings, as applicable, in accordance with their terms, under the laws of the
State of New York which are expressed to govern the same, except as the
enforcement thereof may be limited by bankruptcy, insolvency, reorganization,
moratorium (including, without limitation, all laws relating to fraudulent
transfers), other similar laws relating to or affecting enforcement of
creditors' rights generally, general principles of equity (regardless of whether
enforcement is considered in a proceeding in equity or at law) and limitations
of the waiver of rights under usury laws, and will be entitled to the benefits
of the Indenture.

          We express no opinion as to the validity, legally binding effect or
enforceability of any related provisions of the Indenture or the Exchange Notes
that require or relate to payment of any interest at a rate or in an amount
which a court would determine in the circumstances under applicable law to be
commercially unreasonable or a penalty or a forfeiture. In addition, we express
no opinion as to the validity, legally binding effect or enforceability of the
waiver of rights and defenses contained in the Indenture.

         We are furnishing this opinion letter to you solely in connection with
the registration under the Securities Act by the Company of the Exchange Notes
and by Holdings of the Guarantee. You may not rely on this opinion letter in any
other connection, and it may not be furnished to or relied upon by any other
person for any purpose, without our specific prior written consent.

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WESCO International, Inc.
WESCO Distribution, Inc.
September 27, 2001
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         The foregoing opinions are rendered as of the date of this letter. We
assume no obligation to update or supplement any of such opinions to reflect any
changes of law or fact that may occur.

                                                Yours truly,

                                                /s/ KIRKPATRICK & LOCKHART LLP

                                                KIRKPATRICK & LOCKHART LLP