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                                                                      EXHIBIT 15

November 9, 1999



Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549

RE:       Tollgrade Communications, Inc. and subsidiaries

         1). Form S-8 (Registration No. 333-4290) 1995 Long-Term Incentive
Compensation Plan and Individual Stock Options Granted to Certain Directors and
Employees Prior to the Adoption of the Plan

         2). Form S-8 (Registration No. 333-52907) 1998 Employee Incentive
Compensation Plan

Ladies and gentlemen:

We are aware that our report dated October 8, 1999 on our review of interim
financial information of Tollgrade Communications, Inc. and subsidiaries as of
and for the three months and nine months ended September 25, 1999 and in the
Company's quarterly report on Form 10-Q for the quarter then ended is
incorporated by reference in the registration statement referred to above.

Very truly yours,



/s/ PricewaterhouseCoopers LLP