<PAGE>

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


                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D. C. 20549

                                   FORM 10-Q

                  QUARTERLY REPORT UNDER SECTION 13 OR 15(d)
                    OF THE SECURITIES EXCHANGE ACT OF 1934


        For Quarter ended March 31, 2000 Commission file number 0-5426

                             THE WISER OIL COMPANY
                            A DELAWARE CORPORATION

                 I.R.S. Employer Identification No. 55-0522128

                         8115 Preston Road, Suite 400
                              Dallas, Texas 75225
                           Telephone (214) 265-0080


Former name, former address and former fiscal year, if changed since last
report.   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, and (2) has been subject to such filing requirements
for the past 90 days.

       x
     -----       _____
     Yes          No

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the close of the period covered by this report.

         Class                             Outstanding at March 31, 2000
     -------------                         -----------------------------
     $3 par value                                    8,951,965

================================================================================
<PAGE>

                                                           THE WISER OIL COMPANY


                             THE WISER OIL COMPANY

                                    PART I

                             FINANCIAL INFORMATION

Item 1.   Financial Statements

          The consolidated condensed financial statements included herein have
been prepared by the Company, without audit, pursuant to the rules and
regulations of the Securities and Exchange Commission. The financial statements
reflect all adjustments which are, in the opinion of management, necessary to
fairly present such information. Although the Company believes that the
disclosures are adequate to make the information presented not misleading,
certain information and footnote disclosures, including significant accounting
policies, normally included in financial statements prepared in accordance with
generally accepted accounting principles have been condensed or omitted pursuant
to such rules and regulations. It is suggested that these condensed financial
statements be read in conjunction with the financial statements and the notes
thereto included in the Company's latest annual report on Form 10-K.

                                       2
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY
                          CONSOLIDATED BALANCE SHEETS
                                  (Unaudited)

<TABLE>
<CAPTION>
                                                                March 31,     December 31,
                                                                  2000           1999
                                                                ---------      ---------
                                                                (000's) except share data
<S>                                                             <C>           <C>
Assets
Current Assets:
 Cash and cash equivalents....................................  $  15,509      $  21,447
 Restricted cash..............................................      3,975            992
 Accounts receivable..........................................     11,034          9,565
 Inventories..................................................        336            335
 Prepaid expenses.............................................        925            379
                                                                ---------      ---------
    Total current assets......................................     31,779         32,718
                                                                ---------      ---------

Property, Plant and Equipment, at cost:
 Oil and gas properties (successful efforts method)...........    281,193        274,760
 Other properties.............................................      3,925          3,781
                                                                ---------      ---------
                                                                  285,118        278,541
 Accumulated depreciation, depletion and amortization.........   (122,426)      (118,568)
                                                                ---------      ---------
 Net property, plant and equipment............................    162,692        159,973
Other Assets..................................................      4,135          4,035
                                                                ---------      ---------
                                                                $ 198,606      $ 196,726
                                                                =========      =========

Liabilities and Stockholders' Equity
Current Liabilities:
 Accounts payable.............................................  $  11,096      $  11,694
 Current portion of long-term debt............................        500            500
 Accrued liabilities..........................................      5,362          2,649
                                                                ---------      ---------
   Total current liabilities..................................     16,958         14,843
                                                                ---------      ---------
Long Term Debt................................................    124,544        124,526
Deferred Benefit Cost.........................................        202            216
Deferred Income Taxes.........................................         --             --
Stockholders' Equity:
  Common stock - $3 par value; 20,000,000 shares authorized;
  shares issued - 9,128,169; shares outstanding - 8,951,965...     27,385         27,385
 Paid-in capital..............................................      3,223          3,223
 Retained earnings............................................     27,992         28,234
 Foreign currency translation.................................      1,031          1,028
 Treasury stock; 176,204 shares, at cost......................     (2,729)        (2,729)
                                                                ---------      ---------
   Total stockholders' equity.................................     56,902         57,141
                                                                ---------      ---------
                                                                $ 198,606      $ 196,726
                                                                =========      =========
</TABLE>

     The notes to financial statements included in the Company's Annual Report
     on Form 10-K for the year ended December 31, 1999 are an integral part of
     these financial statements.

                                       3
<PAGE>

                                                           THE WISER OIL COMPANY

                                  THE WISER OIL COMPANY
            CONSOLIDATED STATEMENTS OF INCOME AND RETAINED EARNINGS
                                  (Unaudited)
<TABLE>
<CAPTION>

                                                       For the Three Months
                                                          Ended March 31,
                                                          ---------------
                                                        2000           1999
                                                        ----           ----
                                                   (000's except per share data)
<S>                                           <C>              <C>
Revenues:
  Oil and gas sales.........................         $14,678         $11,605
  Dividends and interest....................             297              26
  Other.....................................             190             240
                                                     -------         -------
                                                      15,165          11,871
                                                     -------         -------

Costs and Expenses:
  Production and operating..................           5,279           5,322
  Purchased natural gas.....................              --             336
  Depreciation, depletion and amortization..           3,802           5,438
  Exploration...............................           1,456             894
  General and administrative................           1,702           1,519
  Interest expense..........................           3,168           3,406
                                                     -------         -------
                                                      15,407          16,915
                                                     -------         -------

Earnings (Loss) Before Income Taxes.........            (242)         (5,044)
Income Tax Expense (Benefit)................              --            (686)
                                                     -------         -------

NET INCOME (LOSS)...........................            (242)         (4,358)

Retained Earnings, beginning of period......          28,234          43,090
Dividends Paid..............................              --              --
                                                     -------         -------
Retained Earnings, end of period............         $27,992         $38,732
                                                     =======         =======

Weighted Average Outstanding Shares.........           8,952           8,952
                                                     =======         =======

Earnings (Loss) Per Share:
  Basic.....................................          $(0.03)         $(0.49)
                                                     =======         =======

  Diluted...................................          $(0.03)         $(0.49)
                                                     =======         =======

Cash Dividends Per Share....................         $    --         $    --
                                                     =======         =======
</TABLE>

     The notes to financial statements included in the Company's Annual Report
     on Form 10-K for the year ended December 31, 1999 are an integral part of
     these financial statements.

                                       4
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY

           CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY

                   For the Three Months Ended March 31, 2000

<TABLE>
<CAPTION>
                                                                           Foreign
                                            Common   Paid-in  Retained    Currency    Treasury
                                  Total     Stock    Capital  Earnings   Translation    Stock
                                ---------  --------  -------  ---------  -----------  ---------
                                                               (000's)
<S>                             <C>        <C>       <C>      <C>        <C>          <C>

December 31, 1999.............   $57,141    $27,385   $3,223   $28,234        $1,028   $(2,729)

  Net income (loss)                 (242)        --       --      (242)           --        --
  Other comprehensive income
     (loss), net of tax.......         3         --       --        --             3        --
                                 -------
Comprehensive income (loss)...      (239)

Dividends paid................        --         --       --        --            --        --
                                 -------   --------  -------  --------   -----------  --------

March 31, 2000................   $56,902    $27,385   $3,223   $27,992        $1,031   $(2,729)
                                 =======   ========  =======  ========   ===========  ========

</TABLE>



The notes to financial statements included in the Company's Annual Report on
Form 10-K for the year ended December 31, 1999 are an integral part of these
financial statements.

                                       5
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY
                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                  (Unaudited)

<TABLE>
<CAPTION>
                                                                   For the Three Months
                                                                     Ended March 31,
                                                                   --------------------
<S>                                                                <C>        <C>
                                                                       2000       1999
                                                                    -------    -------
                                                                          (000's)
Cash Flows From Operating Activities:
   Net Income (Loss).............................................   $  (242)   $(4,358)
   Adjustments to reconcile net income to operating cash flows:
     Depreciation, depletion and amortization....................     3,802      5,438
     Deferred income taxes.......................................        --       (686)
     Property sales losses (gains)...............................       (11)        12
     Foreign currency translation................................         3        (41)
     Property impairments and abandonments.......................       151        405
     Amortization of other assets................................       169        121
     Other Changes:
       Restricted cash...........................................    (2,983)        --
       Accounts receivable.......................................    (1,469)       (47)
       Inventories...............................................        (1)        57
       Prepaid expenses..........................................      (546)      (183)
       Other assets..............................................      (252)        27
       Accounts payable..........................................      (598)    (1,002)
       Accrued liabilities.......................................     2,713      2,811
       Deferred benefits cost....................................       (14)        (9)
                                                                    -------    -------
          Operating Cash Flows...................................       722      2,545
                                                                    -------    -------

Cash Flows From Investing Activities:
   Capital expenditures..........................................    (6,671)    (3,028)
   Proceeds from sales of property, plant and equipment..........        11        318
                                                                    -------    -------
          Investing Cash Flows...................................    (6,660)    (2,710)
                                                                    -------    -------

Cash Flows From Financing Activities:
   Long term debt issued.........................................        --         --
   Dividends paid................................................        --         --
                                                                    -------    -------
          Investing Cash Flows...................................        --         --
                                                                    -------    -------

Net Increase (Decrease) In Cash..................................    (5,938)      (165)
Cash and Cash Equivalents, beginning of period...................    21,447      2,779
                                                                    -------    -------
Cash and Cash Equivalents, end of period.........................   $15,509    $ 2,614
                                                                    =======    =======
</TABLE>

The notes to financial statements included in the Company's Annual Report on
Form 10-K for the year ended December 31, 1999 are an integral part of these
financial statements.

                                       6
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY

Notes to Financial Statements

Note 1.   Hedging Activities

     As of May 15, 2000 the Company's hedging arrangements were as follows:

<TABLE>
<CAPTION>
     Crude Oil:                                        Daily Volume                 Price
     ----------                                        ------------                 -----
     <S>                                            <C>                 <C>
     April 1, 2000 to June 30, 2000                     3,500 Bbls             $22.30 per Bbl
     July 1, 2000 to September 30, 2000                 3,400 Bbls             $21.07 per Bbl
     October 1, 2000 to December 31, 2000               3,300 Bbls             $19.78 per Bbl

     Natural Gas:
     ------------
     February 1, 2000 to September 30, 2000             5,261 MMBTU (1)        $2.29 per MMBTU (1)
     February 1, 2000 to September 30, 2000             5,226 MMBTU (1)(2)     $2.01 (Put) per MMBTU (1)(2)
     March 1, 2000 to September 30, 2000                5,174 MMBTU (1)(2)     $2.20 (Put) per MMBTU (1)(2)
</TABLE>

     (1)  Average for period.

     (2)  The 5,226 MMBTU per day the and 5,174 MMBTU per day natural gas hedges
          are "Put" agreements whereby the Company will receive the actual
          market price if the actual market price is above the put prices of
          $2.01 and $2.20 per MMBTU, respectively. If the actual market price is
          below the put price, the price received by the Company will be limited
          to the put price.

     During the first quarter of 2000, oil and gas sales were reduced $1.4
million from the Company's hedging activities. Based on March 31, 2000 NYMEX
futures prices, the fair value of the Company's hedging arrangements at March
31, 2000 was a loss of $5.3 million. A 10% increase in both the oil price and
the gas price would increase this loss by $2.7 million and a 10% decrease in
both the oil price and the gas price would decrease this loss by $2.7 million.

Note 2.   Convertible Preferred Stock

On December 13, 1999, the Board of Directors approved the sale of not less than
600,000 shares of convertible preferred stock and not more than 1,000,000 shares
of convertible preferred stock through a private placement to Wiser Investment
Company, LLC ("WIC") for $25 million. The convertible preferred stock will be
convertible at the option of the holder into shares of the Company's common
stock at a conversion price of $4.25 per common share, subject to customary
adjustments. The convertible preferred stock will pay dividends in cash or in
shares of the Company's common stock, at the option of the Company, at an annual
rate of 7%. The holders of the convertible preferred stock will have the same
voting rights as the holders of the Company's common stock with each share of
the convertible preferred stock having one vote for each share of common stock
into which it is convertible. Any shares of convertible preferred stock not
previously converted will convert automatically to common stock three years
after the transaction closing date or whenever the market price of the Company's
common stock exceeds $10.00 per share for a period of 60 consecutive trading
days.

                                       7
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY

Notes to Financial Statements (continued)


In addition, WIC will acquire, for a nominal sum, seven-year warrants to
purchase that number of the Company's common stock equal to 741,716 multiplied
by a fraction, of which the numerator is the total number of shares of
convertible preferred stock purchased at the closing and any option closing and
the denominator is 1,000,000, at a purchase price of $0.02 per warrant.  The
strike price of the warrants issued at closing will be $4.25 per share, subject
to adjustment.

The transaction is expected to close upon stockholder approval and the
stockholder vote is scheduled for May 16, 2000. After the closing of the
transaction, the Board of Directors will be changed to include four of the
current directors and three new directors designated by WIC. The transaction
will also constitute a "change of control" as defined in the employment
agreements for all of the officers of the Company. If an officer's employment
with the Company is terminated by either the Company or the officer within one
year after a change of control, the Company will be required to make a lump-sum
termination payment, as defined in the employment agreement, to the terminated
officer. The total amount of such termination payments for all of the Company's
officers is estimated to be in the range of $2.6 million to $3.4 million.

Note 3.   Summary of Guaranties of 9  1/2% Senior Subordinated Notes

     In May 1997, the Company issued $125 million aggregate principal amount of
its 9  1/2% Senior Subordinated Notes due 2007 pursuant to an offering exempt
from registration under the Securities Act of 1933.  The notes are unsecured
obligations of the Company, subordinated in right of payment to all existing and
any future senior indebtedness of the Company.  The notes rank pari passu with
any future senior subordinated indebtedness and senior to any future junior
subordinated indebtedness of the Company.  The notes are fully and
unconditionally guaranteed, jointly and severally, on an unsecured, senior
subordinated basis by certain wholly owned subsidiaries of the Company (the
"Subsidiary Guarantors").  At the time of the initial issuance of the notes,
Wiser Oil Delaware, Inc., The Wiser Marketing Company, Wiser Delaware LLC,
T.W.O.C., Inc. and The Wiser Oil Company of Canada were the Subsidiary
Guarantors (the "Initial Subsidiary Guarantors").  Except for five wholly owned
subsidiaries that are inconsequential to the Company on a consolidated basis,
the Initial Subsidiary Guarantors comprise all of the Company's direct and
indirect subsidiaries.

     Sections 13 and 15(d) of the Securities Exchange Act of 1934 require
presentation of the following unaudited summarized financial information of the
Subsidiary Guarantors.  The Company has not presented separate  financial
statements and other disclosures concerning each Subsidiary Guarantor because
management has determined that they are not material to investors.  There are no
significant contractual restrictions on distributions from each of the
Subsidiary Guarantors to the Company.

                                       8
<PAGE>

                                                           THE WISER OIL COMPANY


                             THE WISER OIL COMPANY

Notes to Financial Statements (continued)

<TABLE>
<CAPTION>
                                                  THE WISER OIL COMPANY
                                                             Subsidiary Guarantors
                                                   ------------------------------------------
                                                                         The Wiser
                                                     Wiser     T.W.O.C.  Marketing  Combined
                                                   Canada(1)     Inc.     Company     Total
                                                   ----------  --------  ---------  ---------
(000's)
<S>                                                <C>         <C>       <C>        <C>
Revenues
--------
For the quarter ended March 31, 2000............   $ 5,294      $     -    $     -  $  5,294
For the quarter ended March 31, 1999............     3,158            -          -     3,158

Income (Loss) Before Income Taxes
---------------------------------
For the quarter ended March 31, 2000............     1,181            -          -     1,181
For the quarter ended March 31, 1999............      (510)           -          -      (510)

Net Income (Loss)
-----------------
For the quarter ended March 31, 2000............     1,181            -          -     1,181
For the quarter ended March 31, 1999............      (510)           -          -      (510)

Cash Flows from Operating Activities
------------------------------------
For the quarter ended March 31, 2000............     2,484            -          -     2,484
For the quarter ended March 31, 1999............     1,995            -          -     1,995

Cash Flows from Investing Activities
--------------------------------------
For the quarter ended March 31, 2000............    (3,849)           -          -    (3,849)
For the quarter ended March 31, 1999............    (2,510)           -          -    (2,510)

Cash Flows from Financing Activities
------------------------------------
For the quarter ended March 31, 2000............         -            -          -         -
For the quarter ended March 31, 1999............         -            -          -         -

Net Increase (Decrease) in Cash
-------------------------------
For the quarter ended March 31, 2000............    (1,365)           -          -    (1,365)
For the quarter ended March 31, 1999............      (515)           -          -      (515)

Current Assets
--------------
March 31, 2000..................................     5,071            3          -     5,074
December 31, 1999...............................     5,357            3          -     5,360

Total Assets
------------
March 31, 2000..................................    50,021            3          -    50,024
December 31, 1999...............................    47,953            3          -    47,956

Current Liabilities
-------------------
March 31, 2000..................................     5,996            -          -     5,996
December 31, 1999...............................     5,116            -          -     5,116
</TABLE>

                                       9
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY

Notes to Financial Statements (continued)

<TABLE>
<CAPTION>
                                                             THE WISER OIL COMPANY
                                                             Subsidiary Guarantors
                                                   ------------------------------------------
                                                                          The Wiser
                                                      Wiser     T.W.O.C.  Marketing  Combined
                                                    Canada(1)     Inc.     Company    Total
                                                   -----------  --------  ---------  --------
(000's)
<S>                                                <C>          <C>       <C>        <C>
Noncurrent Liabilities
----------------------
March 31, 2000..................................    $18,454      $     -    $     -   $18,454
December 31, 1999...............................     17,851            -          -    17,851

Stockholder's Equity
--------------------
March 31, 2000..................................     25,688            3          -    25,691
December 31, 1999...............................     24,986            3          -    24,989
</TABLE>

(1)  Includes the accounts of Wiser Oil Delaware, Inc., Wiser Delaware LLC and
     The Wiser Oil Company of Canada.

See other notes to financial statements included in the Company's Annual Report
on Form 10-K for the year ended December 31, 1999.

Item 2.   Management's Discussion and Analysis of Financial Condition and
          Results of Operations

        Comparison of Quarters Ended March 31, 2000 and March 31, 1999

     Revenues for the first quarter of 2000 increased $3.3 million or 28% from
the first quarter of 1999, due to significantly higher oil and gas prices
received in the first quarter of 2000 which offset lower oil and gas production.
Oil sales for the first quarter of 2000 were $3.0 million higher than the first
quarter of 1999 as the average price received for oil sales in the first quarter
of 2000 was $23.54 per barrel, up $12.60 per barrel or 115% from the first
quarter of 1999.  Net oil production for the first quarter of 2000 was 362,000
barrels, down 137,000 barrels or 27% from 499,000 barrels in the first quarter
of 1999. The property sales in the second quarter of 1999 accounted for
approximately 36,000 barrels of the decline in oil production and oil production
from the  Maljamar and Wellman fields in the first quarter of 2000 was
approximately 40,000 barrels lower than the first quarter of 1999. Canadian oil
production in the first quarter of 2000 was approximately 55,000 barrels lower
than the first quarter of 1999 due primarily to declining oil production from
the Provost and Evi fields. Gas sales for the first quarter of 2000 were $0.6
million lower than the first quarter of 1999 due to lower gas production which
was partially offset by higher realized prices. Gas production for the first
quarter of 2000 was 2,242 MMCF, down 1,062 MMCF or 32% from the first quarter of
1999. The property sales in the second quarter of 1999 accounted for
approximately 818 MMCF of the decline in gas production and gas production from
the South Texas field in the first quarter of 2000 was approximately 104 MMCF
lower than the first quarter of 1999. The average price received for gas sales
during the first quarter of 2000 was $2.22 per mcf, an increase of $0.54 per mcf
or 32% from the first quarter of 1999. Oil and gas sales were reduced by $1.4
million in the first quarter of 2000 and  increased by $0.1 million in the first
quarter of 1999 from the Company's hedging activities.

                                       10
<PAGE>

                                                           THE WISER OIL COMPANY


                             THE WISER OIL COMPANY

Item 2.   Management's Discussion and Analysis of Financial Condition and
          Results of Operations

Comparison of Quarters Ended March 31, 2000 and March 31, 1999 (continued)

     Production and operating expense for the first quarter of 2000 decreased
only 1% from the first quarter of 1999. The property sales in the second quarter
of 1999 accounted for a decrease in production and operating expense of
approximately $0.8 million which was offset by higher production and operating
expense at the Maljamar and Wellman fields of approximately $1.0 million. The
higher production and operating expense at the Maljamar and Wellman fields in
the first quarter of 2000 was attributable to well repairs and maintenance at
both fields and higher CO2 injection at Wellman. On a BOE basis (excluding 148
MMCF of gas purchased for resale during the first quarter of 1999), production
and operating expense during the first quarter of 2000 increased to $6.65 per
BOE or 37% from $4.85 per BOE during the first quarter of 1999. Depreciation,
depletion and amortization, ("DD&A") for the first quarter of 2000, decreased
$1.6 million or 30% from the first quarter of 1999 due primarily to the property
sales in the second quarter of 1999. Exploration expense for the first quarter
of 2000 was $1.5 million, up $0.6 million from the first quarter of 1999 due
primarily to approximately $1.0 million of dry hole expense in Canada in the
first quarter of 2000 for the Waskahigan 8-7 well. General and administrative
expense in the first quarter of 2000 was $1.7 million, up $0.2 million from the
first quarter of 1999 due primarily to lower payroll overhead recovery in the
U.S. Interest expense in the first quarter of 2000 was $3.2 million, down $0.2
million from the first quarter of 1999 due to reduced borrowings in the first
quarter of 2000 compared the first quarter of 1999. The net loss before income
taxes of $0.2 million in the first quarter of 2000 and $5.0 million in the first
quarter of 1999 will generate income tax benefits only if the net loss can be
carried forward and applied against future taxable income. Since full
realization of the future income tax benefits associated with the net loss is
not "more likely than not" at this time, income tax benefits were recognized in
the first quarter of 1999 only to the extent of the Company's existing deferred
income tax liability of $0.7 million.

     The Company realized a net loss of $0.2 million and net loss per share of
$0.03 in the first quarter of 2000 compared to a net loss of $4.4 million and
net loss per share of $0.49 during the first quarter of 1999.

     Operating cash flows during the first quarter of 2000 were $0.7 million,
down $1.8 million from the first quarter of 1999. Higher oil and gas sales
increased cash flows from operations by $3.1 million while changes in restricted
cash and working capital decreased cash flows from operations by $4.5 million.
Capital expenditures during the first quarter of 2000 were $6.7 million, up $3.7
million from $3.0 million in the first quarter of 1999. The Company's capital
and exploration budget for 2000 is approximately $15 million. On a cash basis,
the Company paid $0.03 million in interest expense in the first quarter of 2000
and no income taxes were paid in the first quarter of 2000.

Item 3.  Quantitative and Qualitative Disclosures About Market Risk

     See Note 1 "Hedging Activities."

                                       11
<PAGE>

                                                           THE WISER OIL COMPANY


                             THE WISER OIL COMPANY

                          PART II - OTHER INFORMATION



ITEM 6.   EXHIBITS AND REPORTS ON FORM 8-K

     (a)  Exhibits
          --------
          The information required by this Item 6 (a) is set forth in the Index
          to Exhibits accompanying this quarterly report and is incorporated
          herein by reference.

     (b)  Reports on Form 8-K
          -------------------
          1. The Company filed a report on Form 8-K on March 20, 2000 disclosing
          under Item 5. thereof that the Company entered into an Amended and
          Restated Stock Purchase Agreement and Amended and Restated Warrant
          Purchase Agreement, each dated as of December 13, 1999, with Wiser
          Investment Company, LLC.

          2. The Company filed a report on Form 8-K on March 20, 2000 disclosing
          under Item 5. thereof that the Company entered into Purchase and Sale
          Agreements dated April 12, 1999 and April 13, 1999 with Columbia
          Natural Resources and Prince Minerals, Ltd, respectively, whereof the
          Company sold certain of its oil and gas properties.


                                       12
<PAGE>

                                                           THE WISER OIL COMPANY


                                  SIGNATURES
                                  ----------

Pursuant to the requirements 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.



                                        THE WISER OIL COMPANY
                                      --------------------------
                                         (Registrant)



Date:  May 15, 2000                     /s/ Andrew J. Shoup, Jr.
                                      --------------------------
                                          Andrew J. Shoup, Jr.
                                          President and
                                          Chief Executive Officer



Date:  May 15, 2000                    /s/ Lawrence J. Finn
                                      --------------------------
                                         Lawrence J. Finn
                                         Vice President, Finance and
                                         Chief Financial Officer

                                       13
<PAGE>

                                                           THE WISER OIL COMPANY

                             THE WISER OIL COMPANY

                               Index to Exhibits

Exhibit
Number    Exhibit
------    -------

27        Financial Data Schedule

+ Filed herewith.

                                       14