<PAGE>   1

  AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 13, 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)

                                     ------

                    1998 EMPLOYEE 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,            200,000             $33.625(2)            $6,725,000            $1,681.25
$.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. 1998 Employee 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 February 9, 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
200,000 shares of Common Stock, par value $.20 per share, being offered under
the Tollgrade Communications, Inc. (the "Company") 1998 Employee Incentive
Compensation Plan (the "Plan").

         The contents of the Company's initial Form S-8 Registration Statement
with respect to the Plan, File No. 333-52907, which was filed with the
Securities and Exchange Commission on May 18, 1998, and the Post-Effective
Amendment No. 1 to Form S-8 Registration Statement with respect to the Plan,
File No. 333-52907, 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.

   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
February 9, 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 February 9, 2001.


SIGNATURE                                            TITLE
---------                                            -----

    /s/ Christian L. Allison              Director, Chairman of the Board,
-------------------------------------     Chief Executive Officer
Christian L. Allison                      Principal Executive Officer)


    /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-
<PAGE>   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-
<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                        6
                    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,                  7
                    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": "333-55470", "film-number": "1535967"}, "business-address": {"street1": "493 NIXON RD", "city": "CHESWICK", "state": "PA", "zip": "15024", "phone": "4122742156"}}
1

  AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 13, 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)

                                     ------

                    1998 EMPLOYEE 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,            200,000             $33.625(2)            $6,725,000            $1,681.25
$.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. 1998 Employee 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 February 9, 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
200,000 shares of Common Stock, par value $.20 per share, being offered under
the Tollgrade Communications, Inc. (the "Company") 1998 Employee Incentive
Compensation Plan (the "Plan").

         The contents of the Company's initial Form S-8 Registration Statement
with respect to the Plan, File No. 333-52907, which was filed with the
Securities and Exchange Commission on May 18, 1998, and the Post-Effective
Amendment No. 1 to Form S-8 Registration Statement with respect to the Plan,
File No. 333-52907, 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.

   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
February 9, 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 February 9, 2001.

SIGNATURE                                            TITLE
---------                                            -----

    /s/ Christian L. Allison              Director, Chairman of the Board,
-------------------------------------     Chief Executive Officer
Christian L. Allison                      Principal Executive Officer)

    /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                        6
                    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,                  7
                    filed herewith.

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