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                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                             ---------------------

                                  FORM 10-K/A

<Table>
<C>          <S>
(Mark One)
    [X]      ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)
             OF THE SECURITIES EXCHANGE ACT OF 1934



             FOR THE FISCAL YEAR ENDED DECEMBER 31, 2001



                                   OR




    [ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
             OF THE SECURITIES EXCHANGE ACT OF 1934
</Table>

                         COMMISSION FILE NUMBER 1-8033

                          PERMIAN BASIN ROYALTY TRUST
   (Exact name of Registrant as Specified in the Permian Basin Royalty Trust
                                   Indenture)
                             ---------------------

<Table>
<S>                                            <C>
                    TEXAS                                        75-6280532
       (State or Other Jurisdiction of                        (I.R.S. Employer
        Incorporation or Organization)                      Identification No.)
</Table>

                             BANK OF AMERICA, N.A.
                                TRUST DEPARTMENT
                                P.O. BOX 830650
                              DALLAS, TEXAS 75202
               (Address of Principal Executive Offices; Zip Code)

                                 (214) 209-2400
              (Registrant's Telephone Number, Including Area Code)

          SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:

<Table>
<Caption>
             TITLE OF EACH CLASS                 NAME OF EACH EXCHANGE ON WHICH REGISTERED
             -------------------                 -----------------------------------------
<S>                                            <C>
         Units of Beneficial Interest                     New York Stock Exchange
</Table>

          SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:
                                      NONE

     Indicate by check mark whether the registrant: (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes [X]     No [ ]

     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.  [X]

     At March 1, 2002, there were 46,608,796 Units of Beneficial Interest of the
Trust outstanding with an aggregate market value on that date of $241,899,651.

                      DOCUMENTS INCORPORATED BY REFERENCE

     "Units of Beneficial Interest" at page 1; "Trustee's Discussion and
Analysis for the Three-Year Period Ended December 31, 2001" at pages 7 through
8; "Results of the 4th Quarters of 2001 and 2000" at pages 8 through 9; and
"Statements of Assets, Liabilities and Trust Corpus," "Statements of
Distributable Income," "Statements of Changes in Trust Corpus," "Notes to
Financial Statements" and "Independent Auditors' Report" at page 10 et seq., in
registrant's Annual Report to security holders for fiscal year ended December
31, 2001 are incorporated herein by reference for Item 5, Item 7 and Item 8 of
Part II of this Report.
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<PAGE>

ITEM 9.  CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND
         FINANCIAL DISCLOSURE

     There have been no changes in accountants and no disagreements with
accountants on any matter of accounting principles or practices or financial
statement disclosures during the twenty-four months ended December 31, 2001.

                                    PART III

ITEM 10.  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

     The Trust has no directors or executive officers. The Trustee is a
corporate trustee which may be removed, with or without cause, at a meeting of
the Unit holders, by the affirmative vote of the holders of a majority of all
the Units then outstanding.

ITEM 11.  EXECUTIVE COMPENSATION

     During the years ended December 31, 2001, 2000 and 1999, the Trustee
received total remuneration as follows:

<Table>
<Caption>
                                                      CAPACITIES IN       CASH
NAME OF INDIVIDUAL OR NUMBER OF PERSONS IN GROUP      WHICH SERVED    COMPENSATION   YEAR
------------------------------------------------      -------------   ------------   ----
<S>                                                   <C>             <C>            <C>
Bank of America, N.A................................     Trustee        $40,272(1)   1999
                                                                        $57,680(1)   2000
                                                                        $53,796(1)   2001
</Table>

---------------

(1) Under the Trust Indenture, the Trustee is entitled to an administrative fee
    for its administrative services, preparation of quarterly and annual
    statements with attention to tax and legal matters of: (i) 1/20 of 1% of the
    first $100 million and (ii) Trustee's standard hourly rate in excess of 300
    hours annually. The administrative fee is subject to reduction by a credit
    for funds provision.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

     (a) Security Ownership of Certain Beneficial Owners.  The following table
sets forth as of March 1, 2002, information with respect to each person known to
own beneficially more than 5% of the outstanding Units of the Trust:

<Table>
<Caption>
                                                      AMOUNT AND NATURE OF
NAME AND ADDRESS                                      BENEFICIAL OWNERSHIP   PERCENT OF CLASS
----------------                                      --------------------   ----------------
<S>                                                   <C>                    <C>
Burlington Resources Oil & Gas Company(1)...........   27,577,741 Units           59.17%
5051 Westheimer, Suite 1400
Houston, Texas 77056-2124
McMorgan & Company(2)...............................    5,000,000 Units           10.73%
One Bush Street, Suite 800
San Francisco, CA 94104
</Table>

---------------

(1) This information was provided to the Securities and Exchange Commission and
    to the Trust in a Form 4 dated January 6, 1994, filed with the Securities
    and Exchange Commission by Southland Royalty, a wholly-owned subsidiary of
    BRI, and in Amendment 5 to Schedule 13D and Schedule 13E-3 dated December
    28, 1993, filed with the Securities and Exchange Commission by Southland
    Royalty and BRI. Such Units were reported to be owned directly by Southland
    Royalty, now BROG.

    The Form 4 filed by Southland Royalty and the Schedule 13D and Schedule
    13E-3 filed by Southland Royalty and BRI with the Securities and Exchange
    Commission may be reviewed for more detailed information concerning the
    matters summarized herein.

                                        11
<PAGE>

(2) This information was provided to the Securities and Exchange Commission and
    to the Trust in a Schedule 13G filed with the Securities and Exchange
    Commission on July 12, 1999 on behalf of McMorgan & Company, an investment
    adviser registered under the Investment Advisers Act of 1940, (McMorgan),
    Thomas Allan Morton ("Morton"), and Terry Allen O'Toole ("O'Toole"). Such
    Schedule 13G reports that McMorgan, Morton, and O'Toole have beneficial
    ownership of such Units. It is reported in such Schedule 13G that McMorgan,
    Morton, and O'Toole have sole voting and sole dispositive power with regard
    to such Units. Morton and O'Toole filed in their capacities as control
    persons of McMorgan and disclaimed beneficial ownership to such Units
    involved in such Schedule 13G. The address of Morton and O'Toole is One Bush
    Street, Suite 800, San Francisco, California 94104. Subsequent to the filing
    of such Schedule 13G, McMorgan has informed the Trust that it is no longer
    the beneficial owner of such Units.

    The Schedule 13G filed with the Securities and Exchange Commission on behalf
    of McMorgan, Morton, and O'Toole may be reviewed for more detailed
    information concerning the matters summarized herein.

     (b) Security Ownership of Management.  The Trustee owns beneficially no
securities of the Trust. In various fiduciary capacities, Bank of America, N.A.
owned as of March 1, 2002, an aggregate of 193,796 Units with no right to vote
88,794 of these Units, shared right to vote 2,002 of these Units and sole right
to vote 103,000 of these Units. Bank of America, N.A., disclaims any beneficial
interests in these Units. The number of Units reflected in this paragraph
includes Units held by all branches of Bank of America, N.A.

     (c) Change In Control.  The Trustee knows of no arrangements which may
subsequently result in a change in control of the Trust.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

     The Trust has no directors or executive officers. See Item 11 for the
remuneration received by the Trustee during the years ended December 31, 2001,
2000 and 1999 and Item 12(b) for information concerning Units owned by Bank of
America, N.A. in various fiduciary capacities.

                                    PART IV

ITEM 14.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

     The following documents are filed as a part of this Report:

     1. Financial Statements

     Included in Part II of this Report by reference to the Annual Report of the
Trust for the year ended December 31, 2001:

        Independent Auditors' Report

        Statements of Assets, Liabilities and Trust Corpus at December 31, 2001
        and 2000

        Statements of Distributable Income for Each of the Three Years in the
        Period Ended December 31, 2001

        Statements of Changes in Trust Corpus for Each of the Three Years in the
        Period Ended December 31, 2001

        Notes to Financial Statements

     2. Financial Statement Schedules

     Financial statement schedules are omitted because of the absence of
conditions under which they are required or because the required information is
given in the financial statements or notes thereto.

                                        12
<PAGE>

                                   SIGNATURE

     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.

                                          PERMIAN BASIN ROYALTY TRUST

                                          By: Bank of America, N.A., Trustee

                                          By        /s/ RON E. HOOPER
                                            ------------------------------------
                                                       Ron E. Hooper
                                                   Senior Vice President

Date: March 26, 2002

              (The Trust has no directors or executive officers.)

                                        14