<PAGE>   1
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 20, 2001.

                                                      REGISTRATION NO.
================================================================================


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                         TOLLGRADE COMMUNICATIONS, INC.
             (Exact name of registrant as specified in its charter)

         PENNSYLVANIA                                       25-1537134
(State or other jurisdiction of                          (I.R.S. Employer
incorporation or organization)                           Identification No.)

                                 493 NIXON ROAD
                          CHESWICK, PENNSYLVANIA 15024
                                  412-820-1400
       (Address, including ZIP Code, and telephone number, including area
               code, of registrant's principal executive offices)

                   1995 LONG-TERM INCENTIVE COMPENSATION PLAN

                              CHRISTIAN L. ALLISON
                             CHIEF EXECUTIVE OFFICER
                         TOLLGRADE COMMUNICATIONS, INC.
                                 493 NIXON ROAD
                          CHESWICK, PENNSYLVANIA 15024
                                  412-820-1400
            (Name, address, including ZIP Code, and telephone number,
                   including area code, of agent for service)

                                    Copy to:
                           JEFFREY G. AROMATORIO, ESQ.
                                 REED SMITH LLP
                                435 SIXTH AVENUE
                              PITTSBURGH, PA 15219
                                  412-288-3364

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
                                               Proposed                  Proposed                 Amount of
Securities to be        Amount to be       Maximum Offering          Maximum Aggregate          Registration
Registered               Registered(1)      Price per share           Offering Price                 Fee
----------------------------------------------------------------------------------------------------------------
<S>                    <C>                <C>                       <C>                        <C>
Common Stock,             275,000             $23.375(2)                 $6,428,125                $1607.03
$.20 par value
----------------------------------------------------------------------------------------------------------------
</TABLE>

--------
1    Together with an indeterminate number of additional shares that may be
     necessary to adjust the number of shares reserved for issuance under the
     Tollgrade Communications, Inc. 1995 Long-Term Incentive Compensation Plan
     as a result of any future stock split, stock dividend or similar adjustment
     of the outstanding Common Stock.

2    Estimated solely for the purposes of calculating the amount of the
     registration fee. Pursuant to Rules 457(h) and (c), the proposed maximum
     aggregate offering price for shares subject to stock options outstanding is
     based on the actual option price and for shares which may be issued but are
     not subject to outstanding stock options is based on the average of the
     high and low sales prices of the Common Stock as reported by the NASDAQ
     National Market Issues listing for July 16, 2001 as quoted in The Wall
     Street Journal.

================================================================================

<PAGE>   2




                                     PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         This Form S-8 Registration Statement is being filed pursuant to
paragraph E of the general instructions to Form S-8 to register an additional
275,000 shares of Common Stock, par value $.20 per share, being offered under
the Tollgrade Communications, Inc. (the "Company") 1995 Long-Term Incentive
Compensation Plan (the "1995 Plan").

         The contents of the Company's initial Form S-8 Registration Statement
with respect to the 1995 Plan, File No. 333-04290, which was filed with the
Securities and Exchange Commission on May 1, 1996, the Post-Effective Amendment
No. 1 to Form S-8 Registration Statement with respect to the 1995 Plan, File No.
333-04290, which was filed with the Securities and Exchange Commission on July
18, 1997, and the Form S-8 Registration Statement with respect to the 1995 Plan,
File No. 333-83007, which was filed with the Securities and Exchange Commission
on July 16, 1999, are hereby incorporated by reference to this Form S-8
Registration Statement, except to the extent modified below.


ITEM 8.  EXHIBITS.

  Exhibit No.
  -----------
     5.1            Opinion of Reed Smith LLP regarding legality of shares of
                    the Company's Common Stock being registered.

     15.1           Letter re unaudited interim financial information

     23.1           Consent of Reed Smith LLP (contained in the opinion filed as
                    Exhibit 5.1 hereto).

     23.2           Consent of PricewaterhouseCoopers LLP, independent
                    accountants, filed herewith.

     24.1           Powers of Attorney (filed herewith as part of the signature
                    pages).



<PAGE>   3



                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the Borough of Cheswick, Commonwealth of Pennsylvania, on July
20, 2001.

                                           TOLLGRADE COMMUNICATIONS, INC.


                                           By: /s/ Christian L. Allison
                                              --------------------------------
                                               Christian L. Allison
                                               Chief Executive Officer

         KNOW ALL MEN BY THESE PRESENTS that each person whose signature appears
below constitutes and appoints Christian L. Allison and Sara M. Antol, and each
of them, his true and lawful attorneys-in-fact and agents, with full power of
substitution and revocation, for him and in his name, place and stead, in any
and all capacities, to sign any and all amendments (including post-effective
amendments) to this Registration Statement, and to file the same with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents, and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary to be done, as fully to all intents
and purposes as he might or could do in person, hereby ratifying and confirming
all that said attorneys-in-fact and agents or any of them, or their substitutes,
may lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on July 20, 2001.

<TABLE>
<CAPTION>
SIGNATURE                                                     TITLE
---------                                                     -----
<S>                                                         <C>
    /s/ Christian L. Allison                                  Director, Chairman of the Board, Chief
-----------------------------------------------------         Executive Officer (Principal Executive Officer)
Christian L. Allison


    /s/ James J. Barnes                                       Director
-----------------------------------------------------
James J. Barnes


    /s/ Daniel P. Barry                                       Director
-----------------------------------------------------
Daniel P. Barry


    /s/ Rocco L. Flaminio                                     Director, Vice Chairman and Chief Technology
-----------------------------------------------------         Officer
Rocco L. Flaminio


    /s/ Richard M. Heibel                                     Director
-----------------------------------------------------
Richard M. Heibel, M.D.


    /s/ Robert W. Kampmeinert                                 Director
-----------------------------------------------------
Robert W. Kampmeinert
</TABLE>



                                      -2-
<PAGE>   4


<TABLE>
<CAPTION>
SIGNATURE                                                     TITLE
---------                                                     -----
<S>                                                          <C>
    /s/ David S. Egan                                         Director
-----------------------------------------------------
David S. Egan


    /s/ Samuel C. Knoch                                       Chief Financial Officer and Treasurer
-----------------------------------------------------         (Principal Financial Officer)
Samuel C. Knoch


    /s/ Bradley N. Dinger                                     Controller (Principal Accounting Officer)
-----------------------------------------------------
Bradley N. Dinger
</TABLE>




                                      -3-
<PAGE>   5



                                  EXHIBIT INDEX
                    (Pursuant to Item 601 of Regulation S-K)


<TABLE>
<CAPTION>
  Exhibit No.                         Description and Method of Filing                           Sequential Page
  -----------                         --------------------------------                           ---------------
<S>                <C>                                                                          <C>
     5.1            Opinion of Reed Smith LLP regarding legality of shares of the
                    Company's Common Stock being registered.

     23.1           Consent of Reed Smith LLP (contained in the opinion filed as
                    Exhibit 5.1 hereto).

     23.2           Consent of PricewaterhouseCoopers LLP, independent accountants,
                    filed herewith.

     24.1           Powers of Attorney (filed herewith as part of the signature pages).
</TABLE>


                                      -4-
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{"company-data": {"conformed-name": "TOLLGRADE COMMUNICATIONS INC \\PA\\", "cik": "0001002531", "assigned-sic": "7385", "irs-number": "251537134", "state-of-incorporation": "PA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-65502", "film-number": "1685093"}, "business-address": {"street1": "493 NIXON RD", "city": "CHESWICK", "state": "PA", "zip": "15024", "phone": "4122742156"}}
1
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 20, 2001.

                                                      REGISTRATION NO.
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                         TOLLGRADE COMMUNICATIONS, INC.
             (Exact name of registrant as specified in its charter)

         PENNSYLVANIA                                       25-1537134
(State or other jurisdiction of                          (I.R.S. Employer
incorporation or organization)                           Identification No.)

                                 493 NIXON ROAD
                          CHESWICK, PENNSYLVANIA 15024
                                  412-820-1400
       (Address, including ZIP Code, and telephone number, including area
               code, of registrant's principal executive offices)

                   1995 LONG-TERM INCENTIVE COMPENSATION PLAN

                              CHRISTIAN L. ALLISON
                             CHIEF EXECUTIVE OFFICER
                         TOLLGRADE COMMUNICATIONS, INC.
                                 493 NIXON ROAD
                          CHESWICK, PENNSYLVANIA 15024
                                  412-820-1400
            (Name, address, including ZIP Code, and telephone number,
                   including area code, of agent for service)

                                    Copy to:
                           JEFFREY G. AROMATORIO, ESQ.
                                 REED SMITH LLP
                                435 SIXTH AVENUE
                              PITTSBURGH, PA 15219
                                  412-288-3364

                         CALCULATION OF REGISTRATION FEE
Proposed                  Proposed                 Amount of
Securities to be        Amount to be       Maximum Offering          Maximum Aggregate          Registration
Registered               Registered(1)      Price per share           Offering Price                 Fee
----------------------------------------------------------------------------------------------------------------
Common Stock,             275,000             $23.375(2)                 $6,428,125                $1607.03
$.20 par value
----------------------------------------------------------------------------------------------------------------
--------
1    Together with an indeterminate number of additional shares that may be
     necessary to adjust the number of shares reserved for issuance under the
     Tollgrade Communications, Inc. 1995 Long-Term Incentive Compensation Plan
     as a result of any future stock split, stock dividend or similar adjustment
     of the outstanding Common Stock.

2    Estimated solely for the purposes of calculating the amount of the
     registration fee. Pursuant to Rules 457(h) and (c), the proposed maximum
     aggregate offering price for shares subject to stock options outstanding is
     based on the actual option price and for shares which may be issued but are
     not subject to outstanding stock options is based on the average of the
     high and low sales prices of the Common Stock as reported by the NASDAQ
     National Market Issues listing for July 16, 2001 as quoted in The Wall
     Street Journal.

================================================================================
2

                                     PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         This Form S-8 Registration Statement is being filed pursuant to
paragraph E of the general instructions to Form S-8 to register an additional
275,000 shares of Common Stock, par value $.20 per share, being offered under
the Tollgrade Communications, Inc. (the "Company") 1995 Long-Term Incentive
Compensation Plan (the "1995 Plan").

         The contents of the Company's initial Form S-8 Registration Statement
with respect to the 1995 Plan, File No. 333-04290, which was filed with the
Securities and Exchange Commission on May 1, 1996, the Post-Effective Amendment
No. 1 to Form S-8 Registration Statement with respect to the 1995 Plan, File No.
333-04290, which was filed with the Securities and Exchange Commission on July
18, 1997, and the Form S-8 Registration Statement with respect to the 1995 Plan,
File No. 333-83007, which was filed with the Securities and Exchange Commission
on July 16, 1999, are hereby incorporated by reference to this Form S-8
Registration Statement, except to the extent modified below.

ITEM 8.  EXHIBITS.

  Exhibit No.
  -----------
     5.1            Opinion of Reed Smith LLP regarding legality of shares of
                    the Company's Common Stock being registered.

     15.1           Letter re unaudited interim financial information

     23.1           Consent of Reed Smith LLP (contained in the opinion filed as
                    Exhibit 5.1 hereto).

     23.2           Consent of PricewaterhouseCoopers LLP, independent
                    accountants, filed herewith.

     24.1           Powers of Attorney (filed herewith as part of the signature
                    pages).
3

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the Borough of Cheswick, Commonwealth of Pennsylvania, on July
20, 2001.

                                           TOLLGRADE COMMUNICATIONS, INC.

                                           By: /s/ Christian L. Allison
                                              --------------------------------
                                               Christian L. Allison
                                               Chief Executive Officer

         KNOW ALL MEN BY THESE PRESENTS that each person whose signature appears
below constitutes and appoints Christian L. Allison and Sara M. Antol, and each
of them, his true and lawful attorneys-in-fact and agents, with full power of
substitution and revocation, for him and in his name, place and stead, in any
and all capacities, to sign any and all amendments (including post-effective
amendments) to this Registration Statement, and to file the same with all
exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents, and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary to be done, as fully to all intents
and purposes as he might or could do in person, hereby ratifying and confirming
all that said attorneys-in-fact and agents or any of them, or their substitutes,
may lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on July 20, 2001.
SIGNATURE                                                     TITLE
---------                                                     -----
/s/ Christian L. Allison                                  Director, Chairman of the Board, Chief
-----------------------------------------------------         Executive Officer (Principal Executive Officer)
Christian L. Allison

    /s/ James J. Barnes                                       Director
-----------------------------------------------------
James J. Barnes

    /s/ Daniel P. Barry                                       Director
-----------------------------------------------------
Daniel P. Barry

    /s/ Rocco L. Flaminio                                     Director, Vice Chairman and Chief Technology
-----------------------------------------------------         Officer
Rocco L. Flaminio

    /s/ Richard M. Heibel                                     Director
-----------------------------------------------------
Richard M. Heibel, M.D.

    /s/ Robert W. Kampmeinert                                 Director
-----------------------------------------------------
Robert W. Kampmeinert
-2-
4
SIGNATURE                                                     TITLE
---------                                                     -----
/s/ David S. Egan                                         Director
-----------------------------------------------------
David S. Egan

    /s/ Samuel C. Knoch                                       Chief Financial Officer and Treasurer
-----------------------------------------------------         (Principal Financial Officer)
Samuel C. Knoch

    /s/ Bradley N. Dinger                                     Controller (Principal Accounting Officer)
-----------------------------------------------------
Bradley N. Dinger
-3-
5

                                  EXHIBIT INDEX
                    (Pursuant to Item 601 of Regulation S-K)
Exhibit No.                         Description and Method of Filing                           Sequential Page
  -----------                         --------------------------------                           ---------------
5.1            Opinion of Reed Smith LLP regarding legality of shares of the
                    Company's Common Stock being registered.

     23.1           Consent of Reed Smith LLP (contained in the opinion filed as
                    Exhibit 5.1 hereto).

     23.2           Consent of PricewaterhouseCoopers LLP, independent accountants,
                    filed herewith.

     24.1           Powers of Attorney (filed herewith as part of the signature pages).
-4-