<PAGE>   1

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                                 UNITED STATES

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   FORM 10-K

(MARK ONE)
[X]   ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                SECURITIES EXCHANGE ACT OF 1934 [FEE REQUIRED]

                  FOR THE FISCAL YEAR ENDED DECEMBER 31, 2000

                                       OR

[  ]   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
                 SECURITIES EXCHANGE ACT OF 1934 [NO FEE REQUIRED]

        FOR THE TRANSITION PERIOD FROM ______________ TO ______________

                          COMMISSION FILE NO. 33-13437

                         DEL TACO INCOME PROPERTIES IV
                       (A CALIFORNIA LIMITED PARTNERSHIP)
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

<TABLE>
<S>                                            <C>

                  CALIFORNIA                                     33-0241855
       (STATE OR OTHER JURISDICTION OF                        (I.R.S. EMPLOYER
        INCORPORATION OR ORGANIZATION)                     IDENTIFICATION NUMBER)

         23041 AVENIDA DE LA CARLOTA
           LAGUNA HILLS, CALIFORNIA                                92653
   (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                      (ZIP CODE)
</TABLE>

       Registrant's telephone number, including area code: (949) 462-9300

        Securities registered pursuant to section 12(b) OF THE ACT: NONE

        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 ___

                      DOCUMENTS INCORPORATED BY REFERENCE

     Portions of the registrant's Form S-11 Registration Statement filed June 5,
1987 are incorporated by reference into Part IV of this report.

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>   2

                                     PART I

ITEM 1. BUSINESS

The partnership is a publicly-held limited partnership organized under the
California Uniform Limited Partnership Act. The partnership's General Partner is
Del Taco, Inc., a California corporation ("General Partner"). The partnership
sold 165,415 units totaling $4.135 million through an offering of limited
partnership units from June 1987 through June 1988. The term of the partnership
agreement is until December 31, 2027 unless terminated earlier by means provided
in the partnership agreement.

The business of the partnership is ownership and leasing of restaurants in
California to Del Taco, Inc. The partnership acquired land and constructed three
Mexican-American restaurants for long-term lease to Del Taco, Inc. Each property
is leased for 32 years on a triple net basis. Rent is equal to twelve percent of
gross sales of the restaurants plus supplemental rent as required by the
partnership agreement. As of December 31, 2000, the partnership had a total of
three properties leased to Del Taco (Del Taco, in turn, has sub-leased one of
the restaurants to a Del Taco franchisee).

The partnership has no full time employees. The partnership agreement assigns
full authority for general management and supervision of the business affairs of
the partnership to the General Partner. The General Partner has a one percent
interest in the profits or losses and distributions of the partnership. Limited
partners have no right to participate in the management or conduct of the
partnership's business affairs.


                                        2

<PAGE>   3

ITEM 2. PROPERTIES

The partnership has acquired three properties with proceeds obtained from the
sale of limited partnership units:

<TABLE>
<CAPTION>
                                                                                                 Date of
                                                Date of                                      Commencement of
Address                City, State            Acquisition        Restaurant Constructed        Operation(1)
-------                -----------            -----------        ----------------------      ---------------
<S>                    <C>                    <C>                <C>                         <C>

Orangethorpe Avenue    Placentia, CA          August 5, 1988     60 seat with drive          March 27, 1989
                                                                 through service window

Lakeshore Drive        Lake Elsinore, CA      February 1, 1989   60 seat with drive          April 18, 1990(2)
                                                                 through service window

Highland Avenue        San Bernardino, CA     December 8, 1989   60 seat with drive          July 13, 1990
                                                                 through service window
</TABLE>

------------
(1)  Commencement of operation is the first date Del Taco, Inc., as lessee,
     operated the facility on the site as a Del Taco restaurant.

(2)  The restaurant is subleased to a franchisee of Del Taco, Inc. and the
     restaurant operates as a Del Taco restaurant.


                                     PART II

ITEM 3. LEGAL PROCEEDINGS

The partnership is not a party to any material pending legal proceedings.

ITEM 4. SUBMISSIONS OF MATTERS TO A VOTE OF SECURITY HOLDERS

None.

ITEM 5. MARKET FOR THE PARTNERSHIP'S COMMON EQUITY AND RELATED SECURITY HOLDER
        MATTERS

The partnership sold 165,415 ($4,135,375) limited partnership units during the
public offering period ended June 3, 1988 and currently has 327 limited partners
of record. There is no public market for the trading of the units. Distributions
made by the partnership to the limited partners during the past three fiscal
years are described in Note 7 to the Notes to the Financial Statements contained
under Item 8.


                                       3
<PAGE>   4

ITEM 6.  SELECTED FINANCIAL DATA

<TABLE>
<CAPTION>
                                                    FOR THE YEAR ENDED DECEMBER 31,
                                 ----------------------------------------------------------------------
                                    2000           1999           1998           1997           1996
                                 ----------     ----------     ----------     ----------     ----------
<S>                              <C>            <C>            <C>            <C>            <C>

Rental revenue                   $  417,251     $  401,101     $  398,071     $  327,956     $  361,980

Interest and other income             4,545          3,223          2,455          2,326          1,244

Net income                          320,106        258,596        254,610        187,583        219,223

Net income per limited
  partnership unit(1)                  1.92           1.55           1.52           1.12           1.31

Cash distributions per
  limited partnership unit             2.29           2.16           1.83           1.70           1.74

Total assets                      2,144,413      2,198,920      2,298,687      2,334,746      2,429,366

Long-term obligations               137,953        137,953        137,953        137,953        137,953
</TABLE>

--------------
(1)  The net income per limited partnership unit was calculated based upon
     165,375 weighted average units outstanding in 2000 and 1999 and 165,415
     weighted average units outstanding in 1998, 1997 and 1996.


                                       4
<PAGE>   5

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS

Liquidity and Capital Resources

The partnership offered limited partnership units for sale between June 1987 and
June 1988. 14.5% of the $4.135 million raised through sale of limited
partnership units was used to pay commissions to brokers and to reimburse the
General Partner for offering costs incurred. Approximately $3 million of the
remaining funds were used to acquire sites and build three restaurants. In
February of 1992, approximately $442,000 raised during the offering but not
required to acquire sites and build restaurants was distributed to the limited
partners.

The three restaurants leased to Del Taco make up almost all of the income
producing assets of the partnership. Therefore, the business of the partnership
is almost entirely dependent on the success of the Del Taco trade name
restaurants that lease the properties. The success of the restaurants is
dependent on a large variety of factors, including, but not limited to, consumer
demand and preference for fast food, in general, and for Mexican-American food
in particular.

Results of Operations

The partnership owns three properties that are under long-term lease to Del Taco
for restaurant operations (Del Taco, in turn, has sub-leased one of the
restaurants to a Del Taco franchisee).


                                       5

<PAGE>   6

ITEM 7. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
        OF OPERATIONS - (Continued)

Results of Operations - Continued

The following table sets forth rental revenue earned by restaurant for the year:

                                               YEAR ENDED DECEMBER 31,
                                          ---------------------------------
                                            2000         1999        1998
                                          --------     --------    --------

Orangethorpe Ave., Placentia, CA          $177,310     $174,429    $172,184

Lakeshore Drive, Lake Elsinore, CA         153,993      142,724     144,180

Highland Ave., San Bernardino, CA           85,948       83,948      81,707
                                          --------     --------    --------

          Total                           $417,251     $401,101    $398,071
                                          ========     ========    ========

The partnership receives rental revenues equal to 12 percent of gross sales from
the restaurants plus supplemental rent as required by the partnership agreement.
The partnership earned rental revenue of $417,251 during the year ended December
31, 2000, which represents an increase of $16,150 from 1999. The increase in
rental revenue was caused primarily by an increase in sales at the restaurants
under lease.

The following table breaks down general and administrative expenses by type of
expense:

                  PERCENTAGE OF TOTAL GENERAL & ADMIN. EXPENSE

                                          Year Ended December 31,
                                   ---------------------------------
                                     2000         1999         1998
                                   -------      -------      -------

Accounting fees                      71.00%       65.78%       64.94%
Distribution of information
  to limited partners                27.07        32.32        33.16
Other                                 1.93         1.90         1.90
                                   -------      -------      -------
                                    100.00%      100.00%      100.00%
                                   =======      =======      =======

General and administrative costs decreased by $142 from 1999 to 2000.

Net income increased by $61,510 from 1999 to 2000 due to the increase in
revenues of $17,472, the decrease in depreciation expense of $43,896 and the
$142 decrease in general and administrative expenses. Depreciation decreased in
2000 because certain equipment became fully depreciated in both 1999 and 1998.

On May 19, 1998, the special limited partner resigned. Consistent with the
partnership agreement, the General Partner assumed the duties and
responsibilities of the special limited partner.


                                       6

<PAGE>   7

ITEM 8. FINANCIAL STATEMENTS

PART I. INFORMATION

                                    INDEX

                                                                     PAGE NUMBER
                                                                     -----------
Report of Independent Public Accountants                                   8

Balance Sheets at December 31, 2000 and 1999                               9

Statements of Income for the years ended
  December 31,  2000, 1999 and 1998                                       10

Statement of Changes in Partners' Equity for
  the three years ended December 31, 2000                                 11

Statements of Cash Flows for the years ended
  December 31, 2000, 1999 and 1998                                        12

Notes to Financial Statements                                          13-17


                                       7

<PAGE>   8

                             [ARTHUR ANDERSEN LOGO]

                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS

To the Partners of
Del Taco Income Properties, IV:

We have audited the accompanying balance sheets of Del Taco Income Properties IV
(a California Limited Partnership) as of December 31, 2000 and 1999, and the
related statements of income, partners' equity and cash flows for the three
years ended December 31, 2000. These financial statements and the schedule
referred to below are the responsibility of the Partnership's management. Our
responsibility is to express an opinion on these financial statements and
schedule based on our audits.

We conducted our audits in accordance with auditing standards generally accepted
in the United States. Those standards require that we plan and perform the audit
to obtain reasonable assurance about whether the financial statements are free
of material misstatement. An audit includes examining, on a test basis, evidence
supporting the amounts and disclosures in the financial statements. An audit
also includes assessing the accounting principles used and significant estimates
made by management, as well as evaluating the overall financial statement
presentation. We believe that our audits provide a reasonable basis for our
opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Del Taco Income Properties IV
as of December 31, 2000 and 1999, and the results of its operations and its
cash flows for the three years ended December 31, 2000 in conformity with
accounting principles generally accepted in the United States.

Our audits were made for the purpose of forming an opinion on the basic
financial statements taken as a whole. The schedule in the index of the
financial statements is presented for purposes of complying with the Securities
and Exchange Commission's rules and is not part of the basic financial
statements. This schedule has been subjected to the auditing procedures applied
in our audits of the basic financial statements and, in our opinion, fairly
states in all material respects, the financial data required to be set forth
therein in relation to the basic financial statements taken as a whole.


/s/ ARTHUR ANDERSEN LLP

Orange County, California
February 23, 2001


                                      8

<PAGE>   9

                          DEL TACO INCOME PROPERTIES IV

                                 BALANCE SHEETS

                                                 DECEMBER 31,
                                        ----------------------------
                                            2000             1999
                                        -----------      -----------

                                     ASSETS

CURRENT ASSETS:
     Cash                               $   108,643      $   100,224
     Receivable from Del Taco, Inc.         108,105          111,622
     Deposits                                   476              400
                                        -----------      -----------
         Total current assets               217,224          212,246
                                        -----------      -----------

PROPERTY AND EQUIPMENT, AT COST:
     Land and improvements                1,236,700        1,236,700
     Buildings and improvements           1,289,860        1,289,860
     Machinery and equipment                484,789          484,789
                                        -----------      -----------
                                          3,011,349        3,011,349
     Less--accumulated depreciation       1,084,160        1,024,675
                                        -----------      -----------
                                          1,927,189        1,986,674
                                        -----------      -----------
                                        $ 2,144,413      $ 2,198,920
                                        ===========      ===========


                       LIABILITIES AND PARTNERS' EQUITY

CURRENT LIABILITIES:
     Payable to limited partners        $    24,200      $    19,309
     Accounts payable                        10,080            7,362
                                        -----------      -----------
         Total current liabilities           34,280           26,671
                                        -----------      -----------
OBLIGATION TO GENERAL PARTNER               137,953          137,953
                                        -----------      -----------

PARTNERS' EQUITY:
     Limited partners                     1,983,592        2,045,087
     General Partner-Del Taco, Inc.         (11,412)         (10,791)
                                        -----------      -----------
                                          1,972,180        2,034,296
                                        -----------      -----------
                                        $ 2,144,413      $ 2,198,920
                                        ===========      ===========

                          The accompanying notes are an
                  integral part of these financial statements.


                                       9

<PAGE>   10

                          DEL TACO INCOME PROPERTIES IV

                              STATEMENTS OF INCOME


                                          YEAR ENDED DECEMBER 31,
                                    ----------------------------------
                                      2000         1999         1998
                                    --------     --------     --------
REVENUES:
     Rent                           $417,251     $401,101     $398,071
     Interest                          3,695        2,698        1,555
     Other                               850          525          900
                                    --------     --------     --------
                                     421,796      404,324      400,526
                                    --------     --------     --------
EXPENSES:
     General and administrative       42,205       42,347       42,168
     Depreciation                     59,485      103,381      103,748
                                    --------     --------     --------
                                     101,690      145,728      145,916
                                    --------     --------     --------
         Net income                 $320,106     $258,596     $254,610
                                    ========     ========     ========
     Net income per limited
        partnership unit            $   1.92     $   1.55     $   1.52
                                    ========     ========     ========


                          The accompanying notes are an
                  integral part of these financial statements.

                                       10

<PAGE>   11

                          DEL TACO INCOME PROPERTIES IV

                    STATEMENT OF CHANGES IN PARTNERS' EQUITY

                       THREE YEARS ENDED DECEMBER 31, 2000

<TABLE>
<CAPTION>
                                       Limited Partners
                                  --------------------------         General
                                   Units            Amount           Partner           Total
                                  -------        -----------        --------        -----------
<S>                               <C>            <C>                <C>             <C>
Balance, December 31, 1997        165,415        $ 2,197,413        $ (9,253)       $ 2,188,160

   Net income                          --            252,064           2,546            254,610

   Cash distributions                  --           (302,932)         (3,059)          (305,991)
                                  -------        -----------        --------        -----------
Balance, December 31, 1998        165,415          2,146,545          (9,766)         2,136,779

   Redemption of units                (40)                --              --                 --

   Net income                          --            256,010           2,586            258,596

   Cash distributions                  --           (357,468)         (3,611)          (361,079)
                                  -------        -----------        --------        -----------
Balance, December 31, 1999        165,375          2,045,087         (10,791)         2,034,296

   Net income                          --            316,905           3,201            320,106

   Cash distributions                  --           (378,400)         (3,822)          (382,222)
                                  -------        -----------        --------        -----------
Balance, December 31, 2000        165,375        $ 1,983,592        $(11,412)       $ 1,972,180
                                  =======        ===========        ========        ===========
</TABLE>

                          The accompanying notes are an
                  integral part of these financial statements.

                                       11

<PAGE>   12

                          DEL TACO INCOME PROPERTIES IV

                            STATEMENTS OF CASH FLOWS

<TABLE>
<CAPTION>
                                                                            YEAR ENDED DECEMBER 31,
                                                                  -------------------------------------------
                                                                    2000              1999             1998
                                                                  ---------        ---------        ---------
<S>                                                               <C>              <C>              <C>
CASH FLOWS FROM OPERATING ACTIVITIES:

Net income                                                        $ 320,106        $ 258,596        $ 254,610
Adjustments to reconcile net income to net
  cash provided by operating activities:
     Depreciation                                                    59,485          103,381          103,748
     Increase in payable to limited partners                          4,891              625           16,181
     Decrease (increase) in receivable from General Partner           3,517           (4,898)         (41,592)
     Increase (decrease) in accounts payable                          2,718            2,091             (859)
     (Increase) decrease in deposits                                    (76)             104             (104)
                                                                  ---------        ---------        ---------
             Net cash provided by operating activities              390,641          359,899          331,984

CASH FLOWS FROM FINANCING ACTIVITIES:

Cash distributions to partners                                     (382,222)        (361,079)        (305,991)
                                                                  ---------        ---------        ---------
NET INCREASE (DECREASE) IN CASH                                       8,419           (1,180)          25,993

BEGINNING CASH BALANCE                                              100,224          101,404           75,411
                                                                  ---------        ---------        ---------
ENDING CASH BALANCE                                               $ 108,643        $ 100,224        $ 101,404
                                                                  =========        =========        =========
</TABLE>


                          The accompanying notes are an
                  integral part of these financial statements.

                                       12

<PAGE>   13

                          DEL TACO INCOME PROPERTIES IV

                          NOTES TO FINANCIAL STATEMENTS

                                DECEMBER 31, 2000


NOTE 1 - ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

THE PARTNERSHIP: Del Taco Income Properties IV (a California limited
partnership) was formed on March 23, 1987, for the purpose of acquiring real
property in California for construction of three Mexican-American restaurants to
be leased under long-term agreements to Del Taco, Inc. (General Partner for
operation under the Del Taco trade name).

BASIS OF ACCOUNTING: The partnership utilizes the accrual method of accounting
for transactions relating to the business of the partnership. Distributions are
made to the General and limited partners in accordance with the provisions of
the partnership agreement (see Note 2).

PROPERTY AND EQUIPMENT: Property and equipment is stated at cost. Depreciation
is computed using the straight-line method over estimated useful lives which are
20 years for land improvements, 35 years for buildings and improvements, and 10
years for machinery and equipment.

The partnership accounts for property and equipment in accordance with Statement
of Financial Accounting Standards (SFAS) No. 121, "Accounting for the Impairment
of Long Lived Assets and for Long Lived Assets to be Disposed of." SFAS 121
requires that long-lived assets be reviewed for impairment whenever events or
changes in circumstances indicate that the carrying value of the asset may not
be recoverable. In evaluating long-lived assets held for use, an impairment loss
is recognized if the sum of the expected future cash flows (undiscounted and
without interest charges) is less than the carrying value of the asset. Once a
determination has been made that an impairment loss should be recognized for
long-lived assets, various assumptions and estimates are used to determine fair
value including, among others, estimated costs of construction and development,
recent sales of comparable properties and the opinions of fair value prepared by
independent real estate appraisers. Long-lived assets to be disposed of are
reported at the lower of carrying amount or fair value less cost to sell.

INCOME TAXES: No provision has been made for federal or state income taxes on
partnership net income, since the partnership is not subject to income tax.
Partnership income is includable in the taxable income of the individual
partners as required under applicable income tax laws. Certain items, primarily
related to depreciation methods, are accounted for differently for income tax
reporting purposes (see Note 6).


                                       13

<PAGE>   14

DEL TACO INCOME PROPERTIES IV

NOTES TO FINANCIAL STATEMENTS - CONTINUED
DECEMBER 31, 2000

NOTE 1 - ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - CONTINUED

NET INCOME PER LIMITED PARTNERSHIP UNIT: Net income per limited partnership unit
is calculated based upon 165,375, 165,375 and 165,415 weighted average units
outstanding in 2000, 1999 and 1998, respectively.

USE OF ESTIMATES: The preparation of the financial statements in conformity with
generally accepted accounting principles requires management to make certain
estimates and assumptions that affect the reported amounts of assets and
liabilities at the date of the financial statements and the reported amounts of
revenues and expenses during the reporting period. Actual results could differ
from those estimates.

NOTE 2 - PARTNERS' EQUITY

Pursuant to the partnership agreement, annual partnership net income or loss is
allocated one percent to the General Partner and 99 percent to the limited
partners. Partnership gains from any sale or refinancing will be allocated one
percent to the General Partner and 99 percent to the limited partners until
allocated gains and profits equal losses, distributions and syndication costs,
and until each class of limited partners receive their priority return as
defined in the partnership agreement. Additional gains will be allocated 12
percent to the General Partner and 88 percent to the limited partners.

NOTE 3 - SITE SELECTION AND DEVELOPMENT FEE

Under terms of the partnership agreement, the General Partner is entitled to
receive a fee in an amount equal to five percent of the gross proceeds of the
offering. The fee shall be for services rendered in connection with site
selection and the design and supervision of construction of improvements to
acquired properties. One percent of the gross proceeds of the offering has been
paid to the General Partner. The remaining four percent of this fee shall be
earned at the time the services are rendered, but shall not be paid and shall be
subordinated to the limited partners' interests until all restaurants have
opened and the limited partners have received certain minimum returns on their
investment, as required by the partnership agreement. It is the policy of the
partnership to accrue the site selection and development fee as an obligation to
the General Partner. No fees were earned for such services during 2000, 1999 and
1998.

Effective January 1, 1999, the special limited partners' (who resigned on May
19, 1998) 40 limited partnership units were redeemed by the Partnership.
Pursuant to the Partnership agreement, the redemption was completed at no cost
to the Partnership.


                                       14

<PAGE>   15

DEL TACO INCOME PROPERTIES IV

NOTES TO FINANCIAL STATEMENTS - CONTINUED
DECEMBER 31, 2000

NOTE 4 - LEASING ACTIVITIES

The partnership leases certain properties for operation of restaurants to Del
Taco, Inc. on a triple net basis. The leases are for terms of 32 years
commencing with the completion of the restaurant facility located on each
property and require monthly rentals equal to 12 percent of the gross sales of
the restaurants. Supplemental rent (as defined in the partnership agreement) may
be earned if certain criteria are met. There is no minimum rental under any of
the leases. The partnership had a total of three properties leased to Del Taco
as of December 31, 2000, 1999 and 1998 (Del Taco, in turn, has subleased one of
the restaurants to a Del Taco franchisee).

The two restaurants operated by Del Taco, for which the partnership is the
lessor, had combined, unaudited sales of $1,782,786, $1,701,670 and $1,697,771
and unaudited net income of $111,954, $114,916 and $107,870 for the years ended
December 31, 2000, 1999 and 1998, respectively. Net income by restaurant
includes charges for general and administrative expenses incurred in connection
with supervision of restaurant operations and interest expense. The one
restaurant operated by a Del Taco franchisee, for which the partnership is the
lessor, had unaudited sales of $1,042,856, $940,462 and $970,008 for the years
ended December 31, 2000, 1999 and 1998, respectively.

NOTE 5 - RELATED PARTIES

The receivable from Del Taco consists of rent accrued for the month of December
2000 as well as supplemental rent. These amounts were collected on January 11,
2001.

The General Partner received $3,822 in distributions relating to its one percent
interest in the partnership for the year ended December 31, 2000.

Del Taco, Inc. serves in the capacity of General Partner in other partnerships
which are engaged in the business of operating restaurants, and three other
partnerships which were formed for the purpose of acquiring real property in
California for construction of Mexican-American restaurants for lease under
long-term agreements to Del Taco, Inc. for operation under the Del Taco trade
name.


                                       15

<PAGE>   16

DEL TACO INCOME PROPERTIES IV

NOTES TO FINANCIAL STATEMENTS - CONTINUED
DECEMBER 31, 2000

NOTE 6 - INCOME TAXES

A reconciliation of financial statement net income to taxable income for each of
the periods is as follows:

                                           2000          1999          1998
                                         --------      --------      --------
Net income per financial statements      $320,106      $258,596      $254,610
Excess book depreciation                   19,131        63,024        63,144
                                         --------      --------      --------
Taxable income                           $339,237      $321,620      $317,754
                                         ========      ========      ========

A reconciliation of partnership equity per the financial statements to net worth
for tax purposes as of December 31, 2000, is as follows:

Partners' equity per financial statements           $1,972,180

Issue costs of limited partnership
  units capitalized for tax purposes                   579,259

Excess book depreciation                               155,268
                                                    ----------
Net worth for tax purposes                          $2,706,707
                                                    ==========


                                       16

<PAGE>   17

DEL TACO INCOME PROPERTIES IV

NOTES TO FINANCIAL STATEMENTS - CONTINUED
DECEMBER 31, 2000


NOTE 7 - CASH DISTRIBUTIONS TO LIMITED PARTNERS

Cash distributions paid to limited partners for the three years ended December
31, 2000 were as follows:

<TABLE>
<CAPTION>
                                                    Cash                 Weighted         Number of Units
                                               Distributions per      Average Number      Outstanding at
                                              Limited Partnership        of Units           the End of
Quarter Ended                                        Unit               Outstanding           Quarter
-------------                                 -------------------     --------------      ---------------
<S>                                           <C>                     <C>                 <C>
December 31, 1997                                   $0.41                 165,415             165,415
March 31, 1998                                       0.53                 165,415             165,415
June 30, 1998                                        0.41                 165,415             165,415
September 30, 1998                                   0.48                 165,415             165,415
                                                    -----
   Total paid in 1998                               $1.83
                                                    =====

December 31, 1998                                   $0.47                 165,375             165,415
March 31, 1999                                       0.85                 165,375             165,375
June 30, 1999                                        0.39                 165,375             165,375
September 30, 1999                                   0.45                 165,375             165,375
                                                    -----
   Total paid in 1999                               $2.16
                                                    =====

December 31, 1999                                   $0.45                 165,375             165,375
March 31, 2000                                       0.90                 165,375             165,375
June 30, 2000                                        0.41                 165,375             165,375
September 30, 2000                                   0.53                 165,375             165,375
                                                    -----
   Total paid in 2000                               $2.29
                                                    =====
</TABLE>

Cash distributions per limited partnership unit were calculated based upon the
weighted average number of units outstanding for each quarter and were paid from
operations. Cash distributions for the quarter ended December 31, 2000 amounted
to $.48 per limited partnership unit and were paid January 22, 2001.


                                       17

<PAGE>   18

                                    PART III

ITEM 9. DISAGREEMENTS ON ACCOUNTING AND FINANCIAL DISCLOSURE

None

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE PARTNERSHIP'S GENERAL PARTNER

(a) & (b) The executive officers and directors of the General Partner and their
          ages are set forth below:

Name                      Title                                             Age
----                      -----                                             ---
Kevin K. Moriarty         Director, Chairman and Chief Executive Officer    54

C. Ronald Petty           President                                         56

Paul W. Hitzelberger      Executive Vice President, Franchise
                            Development/Relations                           56

Robert J. Terrano         Executive Vice President and
                             Chief Financial Officer                        45

James D. Stoops           Executive Vice President, Operations              48

Janet D. Simmons          Senior Vice President, Purchasing                 44

Michael L. Annis          Vice President, Secretary and General Counsel     54

C. Douglas Mitchell       Vice President and Corporate Controller           50

Timothy A. Hackbardt      Vice President, Marketing                         37

Shirlene Lopez            Vice President, Corporate Development             36


The above referenced executive officers and directors of the General Partner
will hold office until the annual meeting of its shareholders and directors,
which is scheduled for the later part of 2001.

(c) None

(d) No family relationship exists between any such director or executive officer
    of the General Partner.

(e) The following is an account of the business experience during the past five
    years of each such director and executive officer:


                                       18

<PAGE>   19

Kevin K. Moriarty, Director, Chairman and Chief Executive Officer of Del Taco,
Inc. Mr. Moriarty began his career with Burger King Corporation in 1974 in
Operations Unit Management. In 1983, he was promoted to Area Manager in New
York, and was subsequently promoted to the Regional Vice President, Chicago
Region in 1985. In 1988, he became Executive Vice President and General Manager
of the North Central Division. Mr. Moriarty served in that position until 1990
when he joined Del Taco, Inc. as President and Chief Executive Officer on July
31, 1990. Mr. Moriarty has served as a Director of the General Partner since
1990.

C. Ronald Petty, President of Del Taco, Inc. Mr. Petty began his career in the
restaurant business in 1973 with McDonald's Corporation. He was employed by
McDonald's in a real estate capacity until 1978. For the next 12 years, Mr.
Petty was in various officer positions with Burger King. These positions
included Vice President of Real Estate, Sr. Vice President of Development,
Region Vice President, Sr. Vice President European Operations, President of
International and President of U.S. Mr. Petty served as President of Miami Subs
from 1990-1992; President and CEO of Denny's 1993-1996; President and CEO of
Peter Piper Pizza 1996-1998; President of Del Taco December 1998-present.

Paul W. Hitzelberger, Executive Vice President, Franchise Development/Relations
of Del Taco, Inc. He was appointed to his current position in December 1995. Mr.
Hitzelberger has responsibility for franchise development and relations. From
1991 to 1995, Mr. Hitzelberger was Executive Vice President, Marketing of Del
Taco, Inc. From September 1988 through September 1989, Mr. Hitzelberger was
Chief Executive Officer of Environmental Marketing Group. Prior to that, Mr.
Hitzelberger was a Vice President of Del Taco, Inc. Prior to joining Del Taco,
Inc., he served as Vice President - Marketing at the department store division
of Lucky Stores, Inc., a major supermarket retailer. Mr. Hitzelberger received a
Master of Business Administration degree from Loyola University in Chicago,
Illinois.

Robert J. Terrano, Executive Vice President and Chief Financial Officer of Del
Taco, Inc. From May 1994 to April 1995, Mr. Terrano served as Chief Financial
Officer for Denny's, Inc. in Spartanburg, S.C. From August 1983 to May 1994, he
served with Burger King Corporation, Miami Florida, in a variety of positions,
most recently as Division Controller. Mr. Terrano joined Del Taco, Inc. in April
1995.

James D. Stoops, Executive Vice President, Operations of Del Taco, Inc. From
1968 to 1991, Mr. Stoops served in a wide variety of Operations positions with
Burger King Corporation with increasing levels of responsibility. In 1985, Mr.
Stoops was appointed Region Vice President/General Manager for the New York
region and served in that position until October of 1990. In January of 1991, he
joined Del Taco, Inc. in his current post.

Janet D. Simmons, Senior Vice President, Purchasing of Del Taco, Inc. From 1979
to 1986, Ms. Simmons was with Denny's Inc. She served in the Research and
Development department in a variety of positions until 1982 when she was
promoted to the position of Purchasing Agent. Ms. Simmons was hired in 1986 as
Manager of Contract Purchasing with Carl Karcher Enterprises, a post she held
until March 1990 when she became Vice President, Purchasing for Del Taco, Inc.
Ms. Simmons has a Bachelor of Science degree in Foods and Nutrition from Cal
State Polytechnic University in Pomona, California.


                                       19

<PAGE>   20

Michael L. Annis, Vice President, Secretary and General Counsel of Del Taco,
Inc. From 1981 to 1986 Mr. Annis served as Regional Real Estate Manager and
Director of Real Estate Services with Taco Bell, Inc. In 1986 he served as
Regional General Manager with Quaker State Minit Lube. In January of 1987 Mr.
Annis joined Red Robin International, Inc. as General Counsel and was
subsequently promoted to Vice President/Secretary and later Vice President Real
Estate Development/Secretary and General Counsel, the position he held until
joining Del Taco, Inc. in December of 1993. Mr. Annis received his J.D. Degree
from Whittier College.

C. Douglas Mitchell, Vice President and Corporate Controller. Mr. Mitchell
joined Del Taco, Inc. in August of 1994 as Controller and was promoted to his
current position in January 1996. From 1990 to 1994, Mr. Mitchell was a Senior
Audit Manager with Coopers & Lybrand. Prior to 1990, Mr. Mitchell held various
positions in finance and accounting with the Geneva Companies (a subsidiary of
Chemical Bank), Zaremba Corporation (a real estate developer) and The Dexter
Corporation (an international manufacturer of specialty materials). Mr. Mitchell
has a Bachelor of Science degree with a major in accounting from the University
of Southern California.

Timothy A. Hackbardt, Vice President, Marketing of Del Taco, Inc. Mr. Hackbardt
joined Del Taco, Inc. in November 1999. From November 1995 to November 1999, he
served as Vice President of Marketing of Taco Time International, Inc., Eugene,
OR. From September 1994 to November 1995, Mr. Hackbardt was Director of
Marketing for Wok Spirit Chinese Delivery restaurants in Newport Beach, CA. From
December 1992 to September 1994, Mr. Hackbardt was Director of Marketing for
Fosters Freeze International, Inc., San Luis Obispo, CA. Prior to then, Mr.
Hackbardt held various positions in the television and radio industry in sales
and sales management. Mr. Hackbardt is a graduate of Central Michigan University
where he received a Bachelor of Applied Arts, majoring in Broadcast and
Cinematic Arts and minoring in Marketing.

Shirlene Lopez, Vice President, Corporate Development & Design of Del Taco, Inc.
Ms. Lopez began her career with Del Taco in 1978 as an hourly employee and
advanced through the ranks to General Manager in 1984. Ms. Lopez was promoted to
the corporate office in 1989 as Human Resource Manager. In 1994, she was
promoted to Executive Project Manager reporting to the CEO and in 1996, to
Director of Corporate Development in charge of all interior image and design.
Ms. Lopez has held her current position since August 1997.

ITEM 11. MANAGEMENT REMUNERATION AND TRANSACTIONS

The partnership has no executive officers or directors and pays no direct
remuneration to any executive officer or director of its General Partner. The
partnership has not issued any options or stock appreciation rights to any
executive officer or director of its General Partner, nor does the partnership
propose to pay any annuity, pension or retirement benefits to any executive
officer or director of its General Partner. The partnership has no plan, nor
does the partnership presently propose a plan, which will result in any
remuneration being paid to any executive officer or director of the General
Partner upon termination of employment.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

(a)  No person of record currently owns more than five percent of limited
     partnership units of the partnership, nor was any person known of by the
     partnership to own of record and beneficially, or beneficially only, more
     than five percent of such securities.

(b)  Neither Del Taco, Inc., nor any executive officer or director of Del Taco,
     Inc. owns any limited partnership units of the partnership.

(c)  The partnership knows of no contractual arrangements, the operation or the
     terms of which may at a subsequent date result in a change in control of
     the partnership, except for provisions in the partnership agreement
     providing for removal of the General Partner by holders of a majority of
     the limited partnership units and if a material event of default occurs
     under the financing agreements of the General Partner.

                                      20

<PAGE>   21

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

(a)  No transactions have occurred between the partnership and any executive
     officer or director of its General Partner.

     During 2000, the following transactions occurred between the partnership
     and the General Partner pursuant to the terms of the partnership agreement.

     (1) The General Partner earned $3,201 as its one percent share of the net
         income of the partnership.

     (2) The General Partner received $3,822 in distributions relating to its
         one percent interest in the partnership.

(b)  During 2000, the partnership had no business relationships with any entity
     of a type required to be reported under this item.

(c)  Neither the General Partner, any director or officer of the General Partner
     or any associate of any such person, was indebted to the partnership at any
     time during 2000 for any amount in excess of $60,000.

(d)  Not applicable.


                                       21


<PAGE>   22

                                     PART IV

ITEM 14(a)(1) AND (2). EXHIBITS, FINANCIAL STATEMENTS SCHEDULES, AND REPORTS ON
                       FORM 8-K

     Financial statement schedules:

     Schedule III - Real Estate and Accumulated Depreciation

     Financial statement schedules other than those referred to above have been
     omitted because they are not applicable or not required.

(b)  No reports on Form 8-K were filed during the last quarter of 2000.

(c)  Exhibits required by Item 601 of Regulation S-K:

     1.  Incorporated herein by reference, Restated Agreement of Limited
         Partnership of Del Taco Income Properties IV filed as Exhibit 3.01 to
         Partnership's Registration Statement on Form S-11 as filed with the
         Securities and Exchange Commission on June 5, 1987.

     2.  Incorporated herein by reference, Amendment to Restated Agreement of
         Limited Partnership of Del Taco Income Properties IV.

     3.  Incorporated herein by reference, Form of Standard Lease to be entered
         into by Partnership and Del Taco, Inc., as lessee, filed as Exhibit
         10.02 to Partnership's Registration Statement on Form S-11 as filed
         with the Securities and Exchange Commission on June 5, 1987.


                                       22

<PAGE>   23
                  DEL TACO INCOME PROPERTIES IV - SCHEDULE III

                    REAL ESTATE AND ACCUMULATED DEPRECIATION
                               DECEMBER 31, 2000

<TABLE>
<CAPTION>
                                                                                Cost
                                                                             capitalized     Gross amount at
                                                     Initial cost           subsequent to    which carried at
                                                      to company             acquisition     close of period
                                             ----------------------------------------------------------------
                                                                                             Land, buildings
   Description                               Land & land      Buildings &      Carrying       & improvements   Accumulated
(All Restaurants)          Encumbrances      improvements     Improvements      costs            Total         depreciation
----------------------------------------------------------------------------------------------------------------------------
<S>                        <C>                <C>             <C>               <C>           <C>              <C>
Placentia, CA                  $ --          $   465,933      $  485,961        $ --           $  951,894        $225,806
Lake Elsinore, CA                --              449,058          468,361         --              917,419         217,629
San Bernardino, CA               --              321,709          335,538         --              657,247         155,906
                            ---------------------------------------------------------------------------------------------
                               $ --          $ 1,236,700      $ 1,289,860       $ --           $2,526,560        $599,341
                            =============================================================================================
</TABLE>

<TABLE>
<CAPTION>
                                                           Life on which
                                                       depreciation in latest
   Description                Date of          Date       income statement
(All Restaurants)           construction     acquired       is computed
--------------------------------------------------------------------------------
<S>                         <C>              <C>       <C>
Placentia, CA                   1988           1988       20 (LI), 35 (BI)
Lake Elsinore, CA               1989           1989       20 (LI), 35 (BI)
San Bernardino, CA              1989           1989       20 (LI), 35 (BI)
</TABLE>

                                                                Accumulated
                                             Restaurants        Depreciation
                                             -----------        ------------
Balances at December 31, 1997:                $2,526,560          $433,537
   Acquisitions                                       --            55,268
   Sales                                              --                --
                                              ----------          --------
Balances at December 31, 1998:                 2,526,560           488,805
   Acquisitions                                       --            55,268
   Sales                                              --                --
                                              ----------          --------
Balances at December 31, 1999:                 2,526,560           544,073
   Acquisitions                                       --            55,268
   Sales                                              --                --
                                              ----------          --------
Balances at December 31, 2000:                $2,526,560          $599,341
                                              ==========          ========


                                       23




<PAGE>   24

                                   SIGNATURES

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



                                            DEL TACO INCOME PROPERTIES IV
                                            a California limited partnership

                                            Del Taco, Inc.
                                            General Partner


Date: March 7, 2001                         Kevin K. Moriarty
                                            ------------------------------------
                                            Kevin K. Moriarty
                                            Director, Chairman and Chief
                                            Executive Officer


Date: March 7, 2001                         Michael L. Annis
                                            ------------------------------------
                                            Michael L. Annis
                                            Vice President, Secretary and
                                            General Counsel


Date: March 7, 2001                         Robert J. Terrano
                                            ------------------------------------
                                            Robert J. Terrano
                                            Executive Vice President and
                                            Chief Financial Officer


Date: March 7, 2001                         C. Douglas Mitchell
                                            ------------------------------------
                                            C. Douglas Mitchell
                                            Vice President and Corporate
                                            Controller


                                       24