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                                                                    EXHIBIT 15



May 11, 2000



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 April 12, 2000 on our review of interim
financial information of Tollgrade Communications, Inc. and subsidiaries as of
and for the three month period ended April 1, 2000 and in the Company's
quarterly report on Form 10-Q for the quarter then ended is incorporated by
reference in the registration statements referred to above.

Very truly yours,


/s/ PricewaterhouseCoopers LLP