<PAGE>   1

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                             -----------------------
                                    FORM 10-K
                                  ANNUAL REPORT
                             -----------------------
         (Mark One)

                  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
             X    SECURITIES EXCHANGE ACT OF 1934 [FEE REQUIRED]
         ------
         For the fiscal year ended December 31, 1997
                                   -----------------
                  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 number 0-20255

                         Mahoning National Bancorp, Inc.
                         -------------------------------
             (Exact name of registrant as specified in its charter)

                     OHIO                                34-1692031
                     ----                                ----------
         (State or other jurisdiction of            (I.R.S. Employer
         incorporation or organization)             Identification Number)

         23 FEDERAL PLAZA, YOUNGSTOWN, OH                 44501-0479
         --------------------------------                 ----------
         (Address of principal executive offices)         (Zip Code)

                                 (330) 742-7000
                                 --------------
                         (Registrant's telephone number)
         Securities registered pursuant to Section 12(b) of the Act:

                                      NONE
                                      ----
         Securities registered pursuant to Section 12(g) of the Act:

                 COMMON STOCK, NO PAR VALUE, STATED VALUE $1.00
                 ----------------------------------------------
                                (Title of Class)

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

         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.

         Yes  X               No
            -----               ------

         The aggregate market value of Common Stock, No Par Value, $1 Stated
Value Per Share, held by non-affiliates on February 28, 1998, was approximately
$233,100,000.

         As of February 28, 1998, there were 6,300,000 shares of Common Stock,
No Par Value, $1 Stated Value Per Share, issued and outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

(1)  Portions of the registrant's Annual Report to Shareholders for the year
     ended December 31, 1997, are incorporated by reference into Parts I, II,
     and IV.

(2)  The Notice of Annual Meeting of Shareholders and Proxy Statement relating
     to the 1998 Annual Meeting of Shareholders of the Corporation on March 17,
     1998, is incorporated by reference into Part III.

<PAGE>   2



Mahoning National Bancorp, Inc.
Form 10-K

                                     PART I

ITEM 1. BUSINESS

     Mahoning National Bancorp, Inc. ("the Registrant") was incorporated in 1992
     under the laws of the state of Ohio as a bank holding company.

     The Registrant has one wholly-owned subsidiary, The Mahoning National Bank
     of Youngstown (Mahoning National), which was organized under the laws of
     the State of Ohio in 1868.

     The Registrant has no employees; however, as of December 31, 1997 Mahoning
     National employed approximately 388 full-time equivalent employees.

     The Registrant and its subsidiary do not have any banking offices in a
     foreign country and with the exception of State of Israel Bonds totaling
     $60 thousand, has no foreign assets, liabilities or related income and
     expense for the years presented.

     A description of the Registrant's business and discussion of operations is
     set forth on pages 32 through 43 of the 1997 Annual Report to Shareholders,
     included in this Form 10-K as Exhibit 13, and is incorporated herein by
     reference.

     The following additional financial information as required under Guide 3
     disclosure is included in this Form 10-K and is incorporated herein by
     reference:

     Items I, II, IV, V - the information required is contained in Management's
     Discussion and Analysis on pages 33 through 43 in the 1997 Annual Report to
     Shareholders, included in this Form 10-K as Exhibit 13, incorporated herein
     by reference.

     Item III - the information required is contained in Management's Discussion
     and Analysis on pages 34 through 37 in the 1997 Annual Report to
     Shareholders, included in this Form 10-K as Exhibit 13, incorporated herein
     by reference. Potential problem loans at December 31, 1997, that were not
     disclosed as nonaccrual, accruing loans 90 days or more past due or
     troubled debt restructurings totaled $2.444 million. These loans represent
     borrowers with possible credit problems that may effect the ability of the
     borrowers to comply with the present loan repayment terms and result in the
     disclosure of such loans pursuant to Item III. C.1. All interest bearing
     assets have been disclosed as required under Item III. C.1. or 2.

     Item VI - the information required can be found on page 13 of the 1997
     Annual Report to Shareholders, included in this Form 10-K as Exhibit 13,
     incorporated herein by reference.

<PAGE>   3


Mahoning National Bancorp, Inc.
Form 10-K

     Item VII - the information required can be found on page 14 Consolidated
     Statements of Financial Condition, for year end balances, and on page 23,
     Note H - Short Term Borrowings, of the 1997 Annual Report to Shareholders,
     included in this Form 10-K as Exhibit 13, incorporated herein by reference.

ITEM 2. PROPERTIES

     The main office of the Registrant and its sole subsidiary, Mahoning
     National, is a thirteen-story office building located at 23 Federal Plaza
     in Youngstown, Ohio. Mahoning National owns both the land and the building
     at this location. The Registrant and Mahoning National occupy, and use for
     banking business 88,343 square feet of the approximately 182,000 square
     feet of usable space. The remainder of the building is leased to business
     and professional tenants.

     In January 1998 the Company consolidated its Southside branch office into
     the South and Midlothian branch office at 525 E. Midlothian Boulevard,
     Youngstown, Ohio. The Southside office building, a two-story, 5,080 square
     foot office building located at 2901 Market Street, Youngstown Ohio was
     sold to a local real-estate management company.

     The Campbell branch office of Mahoning National is located at 809 McCartney
     Road, Campbell, Ohio. This 3,600 square foot office is used strictly for
     banking services. Mahoning National owns both the land and building at this
     location.

     The South and Midlothian branch of Mahoning National is located at 525 E.
     Midlothian, Youngstown, Ohio. This 3,400 square foot office is used
     strictly for banking services. Mahoning National owns both the land and
     building at this location.

     The Kinsman branch office of Mahoning National is located at 8222 Main
     Street, Kinsman, Ohio. This 4,680 square foot office is used strictly for
     banking services. Mahoning National owns both the land and building at this
     location.

     The Brookfield branch office of Mahoning National is located at 579 Bedford
     Road, Brookfield, Ohio. This 3,700 square foot office is used strictly for
     banking services. Mahoning National owns both the land and the building at
     this location.

     The South & 224 branch office of Mahoning National, a 3,460 square foot
     office located at 7235 South Avenue, Youngstown, Ohio is used strictly for
     banking services. Mahoning National owns the building but leases the land
     at this location. The lease on the land at South & 224 expires on 05/31/04
     with two 5 year options.

     The Boardman branch office of Mahoning National is located at 711
     Boardman-Canfield Road, Boardman, Ohio. This 3,500 square foot office
<PAGE>   4

Mahoning National Bancorp, Inc.
Form 10-K

     is used strictly for banking services. Mahoning National owns both the land
     and building at this location.

     The Canfield branch office of Mahoning National is located at 11 Manor Hill
     Drive, Canfield, Ohio. This 3,100 square foot office is used strictly for
     banking services. Mahoning National owns both the land and building at this
     location.

     The Registrant's subsidiary, Mahoning National maintains an additional
     fifteen banking offices which are located in Mahoning and Trumbull Counties
     in northeastern Ohio. All of these locations are leased and used strictly
     for banking services.

     All of the properties owned or leased by the Registrant's subsidiary are
     considered by management to be suitable and adequate for current
     operations.

ITEM 3. LEGAL PROCEEDINGS

     There is no pending material litigation, other than the ordinary routine
     litigation incidental to the business, to which the Registrant or its
     subsidiary is a party to or of which any property is subject to. Further,
     there are no material proceedings to which any director, officer or
     affiliate of the Registrant, or any associate of any such director, officer
     or affiliate is a party adverse to the Registrant or its subsidiary.

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

     No matter was submitted to a vote of security holders of the Registrant
     during the fourth quarter of 1997.

                                     PART II

ITEM 5.  MARKET FOR THE REGISTRANT'S COMMON STOCK AND RELATED STOCKHOLDER
         MATTERS

     Market Information:

     The Company's common shares were traded Over-The-Counter, generally in the
     Youngstown area in 1997 and 1996. Effective January 5, 1998, the Company's
     common shares were listed on The NASDAQ National Market System under the
     symbol "MGNB". Currently the following five brokerage firms serve as market
     makers for the Company's common stock: McDonald & Company Securities, Inc.,
     The Ohio Company, Sandler O'Neill & Partners, L.P., F. J. Morrissey & Co.,
     Inc. and Everen Securities, Inc.

     The prices presented below are bid prices which represent prices between
     broker-dealers and do not include retail mark-ups or mark-downs or any
     commission to the broker-dealer. These prices may not reflect prices in
     actual transactions.


<PAGE>   5

Mahoning National Bancorp, Inc.
Form 10-K
<TABLE>
<CAPTION>
         Quarter                                1997                       1996
                                            High     Low               High      Low

<S>                                      <C>      <C>               <C>      <C>  
         1st                                22.75    21.50             21.13    19.00
         2nd                                22.50    21.50             25.50    20.75
         3rd                                26.25    22.50             26.25    24.50
         4th                                33.00    26.00             25.50    22.50
</TABLE>

     For additional information on the Company's common stock and related
     stockholder matters refer to Note-M on pages 25 and 26 of the 1997 Annual
     Report to Shareholders, included in this Form 10-K as Exhibit 13,
     incorporated herein by reference.

     Holders of Registrant's Stock:

     At the close of business on January 31, 1998 there were approximately 1,608
     stockholders of record of Mahoning National Bancorp, Inc. common stock.

     Dividend Information:

     For the frequency and amount of cash dividends declared in the past two
     years refer to "Common Share Information" on page 1 of the 1997 Annual
     Report to Shareholders, included in this Form 10-K as Exhibit 13, included
     herein by reference. While the Company expects comparable cash dividends
     will be paid in the future, they will be dependent upon earnings, financial
     condition of the Company and other business factors.

          The dividend payout ratio of the Registrant for the past five years
          was as follows:

                              1997 = 33.59%
                              1996 = 30.66%
                              1995 = 29.09%
                              1994 = 29.07%
                              1993 = 30.38%

ITEM 6. SELECTED FINANCIAL DATA

          The selected financial data for each of the five years in the period
          ending December 31, 1997 can be found on pages 12 and 13 in the 1997
          Annual Report to Shareholders, included in this Form 10-K as Exhibit
          13, incorporated herein by reference.



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

          This information is contained on pages 33 through 43 in the 1997
          Annual Report to Shareholders, included in this Form 10-K as Exhibit
          13, incorporated herein by reference.
<PAGE>   6


Mahoning National Bancorp, Inc.
Form 10-K

ITEM 7a. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

     The primary objective of the Company's asset/liability management process
     is to maximize profits through management of the pricing and mix of assets
     and liabilities, while achieving acceptable levels of interest rate risk
     and liquidity risk and providing for adequate capitalization. Due to the
     fact that the assets and liabilities of a financial institution are
     monetary in nature, changes in interest rates and monetary or fiscal policy
     affect its financial condition and have potentially the greatest impact on
     the net income of the Company. The Company's asset/liability management
     program is designed to minimize the impact of sudden and sustained changes
     in interest rates on the net present value (NPV) of equity and net interest
     income.

     The Company's primary market risk exposure is interest rate risk and, to a
     lesser extent, liquidity risk. All of the Company's transactions are
     denominated in U.S. dollars with no specific foreign exchange exposure. The
     Company has minimal agricultural loan assets and therefore would not have a
     specific exposure to changes in commodity prices. The Company has no market
     risk sensitive instruments held for trading purposes.

     As part of its effort to monitor and manage interest rate risk the Company
     uses simulation analysis and net present value analysis. The simulation
     analysis monitors interest rate risk through the impact changes in interest
     rates can have on net income. At December 31, 1997, the Company analyzed
     the effect of a presumed 100 and 200 basis point increase and decrease in
     interest rates through its simulation analysis. The results indicated no
     significant impact on net interest income for 1998, and were within the
     five percent (5%) of net interest income guidelines established by the
     Company. While the results of the simulation indicated no significant
     impact on net interest income over the next twelve months, they did
     indicate the Company to be negatively impacted by rising interest rates and
     positively impacted by falling interest rates due to the liability
     sensitive nature of the balance sheet.

     The NPV analysis is used to measure the Company's interest rate risk by
     computing estimated changes in NPV of its cash flows from assets,
     liabilities and off-balance sheet items in the event of a range of assumed
     changes in market interest rates. NPV represents the market value of equity
     and is equal to the market value of assets minus the market value of
     liabilities, with adjustments made for off-balance sheet items. This
     analysis assesses the risk of loss in market risk sensitive instruments in
     the event of a sudden and sustained 100 to 200 basis point increase or
     decrease in market interest rates. The Board of Directors has adopted an
     interest rate risk policy which establishes maximum changes in the NPV of
     20% in the event of a sudden and sustained 100 to 200 basis point increase
     or decrease in market interest rates. The following table presents the
     Company's projected change in NPV for the various rate shock levels at
     December 31, 1997. All market risk sensitive instruments presented in this
     table are


<PAGE>   7

Mahoning National Bancorp, Inc.
Form 10-K

     held to maturity or available for sale. The Company has no trading
     securities.
<TABLE>
<CAPTION>
     Changes In
     Interest Rate                Change In                       % Change                NPV of Equity/
     (basis points)             NPV of Equity                     In NPV                  NPV of Assets
     --------------------------------------------------------------------------------------------------
<S>                           <C>                              <C>                         <C>   
          -200                   $  14,969                        17.29%                      12.47%
          -100                       8,853                        10.23                       11.82
             0                       2,852                         3.29                       11.18
          +100                      (3,038)                       (3.51)                      10.53
          +200                      (8,819)                      (10.19)                       9.89

</TABLE>

     The above table indicates that at December 31, 1997, in the event of a
     sudden and sustained increase in prevailing market interest rates, the
     Company's NPV would be expected to decrease, and that in the event of a
     sudden and sustained decrease in prevailing market interest rates, the
     Company's NPV would be expected to increase. At December 31, 1997, the
     Company's estimated changes in NPV were within the targets established by
     the Board of Directors.

     As with any method of measuring interest rate risk, certain shortcomings
     are inherent in the NPV approach. For example, although certain assets and
     liabilities may have similar maturities or periods of repricing, they may
     react in different degrees to changes in market interest rates. Also, as a
     result of competition, the interest rates on certain assets and liabilities
     may fluctuate in advance of changes in market interest rates, while
     interest rates on other types of assets and liabilities may lag behind
     changes in market rates. In the event of a change in interest rates,
     expected rates of repayment on assets and early withdrawal levels from
     certificates of deposit would likely deviate from those scheduled. In
     addition, the proportion of adjustable-rate loans in the Bank's portfolio
     could decrease in future periods if market interest rates remain at or
     decrease below current levels due to refinance activity. Further, in the
     event of a change in interest rates, prepayment and early withdrawal levels
     would likely deviate from those assumed in the table. Finally, the ability
     of many borrowers to repay their adjustable-rate debt may decrease in the
     event of an increase in interest rates.

     In order to minimize the potential for adverse effects of material and
     prolonged increases in interest rates on the Company's results of
     operations, management has implemented and continues to monitor asset and
     liability management strategies to better match the maturities and
     repricing terms of the Company's interest-earning assets and
     interest-bearing liabilities. These strategies include: (1) emphasizing the
     origination of adjustable-rate mortgage loans ("ARMs"); and (2) selling a
     portion of its fixed-rate residential mortgage loan originations with
     servicing retained.

     Deposits, which are the Company's primary funding source, are priced based
     upon competitive factors and the availability of prudent lending 



<PAGE>   8

Mahoning National Bancorp, Inc.
Form 10-K

     and investment opportunities. Pursuant to this strategy, the Company has
     generally not offered the highest rates available in its deposit market
     except upon specific occasions and for specific products, to control
     deposit flow or when market conditions have created opportunities to
     attract longer-term deposits at favorable rates. In addition, the Company
     does not pursue an aggressive growth strategy which would force the Company
     to focus exclusively on competitors' rates rather than deposit
     affordability. This policy has assisted the Company in controlling its cost
     of funds. The Company has also adopted a strategy of emphasizing
     transaction deposit account growth as these products are less susceptible
     to repricing in a rising interest rate environment.

     An additional source of liquidity is derived from the Federal Home Loan
     Bank of Cincinnati (FHLB). The FHLB provides short term funding
     alternatives, with an available line of credit of $52.138 million at
     December 31, 1997, and funding for one-to-four family residential mortgage
     loans and allows the Company to better manage its interest rate risk.

     A derivative financial instrument includes futures, forwards, interest rate
     swaps, option contracts and other financial instruments with similar
     characteristics. The Company has not purchased derivative financial
     instruments in the past and does not presently intend to purchase such
     instruments in the near future. However, the Company is party to financial
     instruments with off-balance sheet risk in the normal course of business to
     meet the financing needs of its customers. These financial instruments
     include commitments to extend credit and standby letters of credit. These
     instruments involve to varying degrees, elements of credit and interest
     rate risk in excess of the amount recognized in the consolidated balance
     sheets. The commitments to extend credit generally have fixed expiration
     dates or other termination clauses and may require payment of a fee. Since
     some of these commitments may not be utilized, or utilized in amounts less
     than the total committed, the total commitment amounts do not necessarily
     represent future cash requirements. The majority of the unfunded
     commitments at December 31, 1997 ($153.115 million) are variable rate
     commitments, with approximately 20% or $31 million having fixed rates.
     Standby letters of credit are conditional commitments issued by the Company
     to guarantee the performance of a customer to a third party up to a
     stipulated amount and with specified terms and conditions.

     The Company's exposure to interest rate risk is reviewed on a quarterly
     basis by the Board of Directors and the ALCO. If estimated changes to NPV
     and net interest income are not within the limits established by the Board,
     the Board may direct management to adjust its asset and liability mix to
     bring interest rate risk within board-approved limits.


<PAGE>   9

Mahoning National Bancorp, Inc.
Form 10-K

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

     The Consolidated Financial Statements, Notes to Consolidated Financial
     Statements, and the Report of Independent Auditors can be found on pages 14
     through 29 of the 1997 Annual Report to Shareholders, included in this Form
     10-K as Exhibit 13, incorporated herein by reference. The report of the
     predecessor auditors for the year ended December 31, 1995 is incorporated
     herein by reference as Exhibit 99(a) - Report of Independent Certified
     Public Accountants.

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

     For information regarding the registrants change in accountants in 1996
     refer to Form 8-K dated May 13, 1996, Change in Registrant's Certifying
     Accountant.

                                    PART III

ITEM 10. DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT

     The information set forth under the caption "Election of Directors and
     Information with Respect to Directors and Officers" on pages 2 and 3 of the
     Notice of Annual Meeting and Proxy Statement, included in this Form 10-K as
     Exhibit 99(b), is incorporated herein by reference.

     Listed below are the names, ages, positions held and terms in office for
     the Registrant's executive officers and their positions held with the sole
     subsidiary, The Mahoning National Bank of Youngstown. The executive
     officers of the Registrant and the subsidiary serve at the direction of the
     Board of Directors, and are elected annually by the Board of Directors of
     the appropriate entity.

     Gregory L. Ridler
               Age - 51

               Current Positions - Chairman of the Board, President and Chief
               Executive Officer of Mahoning National Bancorp, Inc. (1992).
               President and Chief Executive Officer of Mahoning National Bank
               (1989).

    Parker T. McHenry
               Age - 64

               Current Positions - Vice President of Mahoning National Bancorp, 
               Inc. (1992). Executive Vice President of Mahoning National Bank
               (1989).

<PAGE>   10


Mahoning National Bancorp, Inc.
Form 10-K

     Richard E. Davies
          Age - 58

          Current Positions - Secretary for Mahoning National Bancorp, Inc.
          (1992). Senior Vice President and Cashier for Mahoning National Bank
          (1989).

     Norman E. Benden, Jr.
          Age - 39

          Current Positions - Treasurer for Mahoning National Bancorp, Inc.
          (1992). Senior Vice President and Chief Financial Officer of Mahoning
          National Bank(1996). 
          Previous five year experience - Senior Vice
          President and Comptroller of Mahoning National Bank (1994), Vice
          President and Comptroller of Mahoning National Bank (1992).

     Compliance with Section 16(a) of the Securities Exchange Act of 1934.

          The information pertaining to compliance with Section 16(a) of the
          Securities Exchange Act of 1934 can be found on page 11 of the Notice
          of Annual Meeting and Proxy Statement, included in this Form 10-K as
          Exhibit 99(b), incorporated herein by reference.

ITEM 11. EXECUTIVE COMPENSATION

          The information pertaining to executive compensation can be found on
          pages 6 through 10 of the Notice of Annual Meeting and Proxy
          Statement, included in this Form 10-K as Exhibit 99(b), incorporated
          herein by reference.

ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

     (a)  Security ownership of certain beneficial owners.

          None

     (b)  Security ownership of management.

          The information pertaining to security ownership of management can be
          found on page 4 of the Notice of Annual Meeting and Proxy Statement,
          included in this Form 10-K as Exhibit 99(b), incorporated herein by
          reference.

          The following details the security ownership of the executive officers
          of the Registrant:

          Richard E. Davies - 3,145 shares of common stock
                              (.050% of class)

<PAGE>   11

Mahoning National Bancorp, Inc.
Form 10-K

          Norman E. Benden, Jr. - 3,459 shares of common stock
                                  (.055% of class)

     (c)  Changes in control.

          There are no contracts or arrangements known to the Registrant, that
          at a subsequent date, could result in a change in control of the
          Registrant.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTION

     The information pertaining to certain relationships and related
     transactions can be found under the caption "Transactions with Management"
     on page 11 of the Notice of Annual Meeting and Proxy Statement, included in
     this Form 10-K as Exhibit 99(b), incorporated herein by reference.

                                     PART IV

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

    (a)  1.    Financial Statements:

               The following consolidated financial statements of the Registrant
               appear on pages 14 through 29 of the Registrant's 1997 Annual
               Report to Shareholders, Exhibit 13 to this Form 10-K, and are
               incorporated herein by reference:
                    Consolidated Statements of Financial Condition -
                             December 31, 1997 and 1996
                    Consolidated Statements of Income -
                        Three years ended December 31, 1997
                    Consolidated Statements of Changes in
                             Stockholders' Equity -
                             Three years ended December 31, 1997
                    Consolidated Statements of Cash Flows -
                             Three years ended December 31, 1997
                    Notes to Consolidated Financial Statements
                    Report of Independent Auditors

        1a.    Report of Predecessor Independent Auditors:
               The report of the predecessor auditors for the year ended
               December 31, 1995 is incorporated herein by reference as Exhibit
               99(a) - Report of Independent Certified Public Accountants.


         2.    Financial Statement Schedules:
               Schedules normally required of Form 10-K are omitted since the
               required information is not applicable, not deemed material or is
               shown in the respective consolidated financial statements or
               notes thereto.
<PAGE>   12

Mahoning National Bancorp, Inc.
Form 10-K

        (b) 1. Reports on Form 8-K:

               No reports on Form 8-K were filed by the Registrant during the
               fourth quarter of 1997. On January 2, 1998, the Registrant filed
               a report on Form 8-K which announced that the Registrant,
               Mahoning National Bancorp, Inc. had listed its shares of common
               stock on the NASDAQ National Market System. The common stock will
               trade under the symbol "MGNB".

        (c)  1.  Exhibits:

                    (2)  Plan of Acquisition, Reorganization, Arrangement,
                         Liquidation or Succession.
                            Not applicable.

                    (3a) The Articles of Incorporation of Mahoning National
                         Bancorp, Inc., filed on the Registrant's Form S-4, File
                         # 33-45045 effective February 11, 1992, in addition
                         Form 8-K, dated March 21, 1995, Certificate of
                         Amendment by Shareholders to the Articles of
                         Incorporation of Mahoning National Bancorp,Inc.,
                         and Form 8-K, dated March 19, 1996, Certificate 
                         of Amendment by Shareholders to the Articles of 
                         Incorporation of Mahoning National Bancorp, Inc., and 
                         Amendment of Article Fourth of the Articles of 
                         Incorporation of Mahoning National Bancorp, Inc., is 
                         incorporated herein by reference.

                    (3b) The Bylaws of Mahoning National Bancorp, Inc., filed on
                         the Registrant's Form S-4, File #33-45045 effective
                         February 11, 1992, is incorporated herein by reference.

                    (4)  Instruments defining the Rights of Security Holders,
                         Including Indentures, filed on the Registrant's Form
                         S-4, File #33-45045 effective February 11, 1992, is
                         incorporated herein by reference.

                    (9)  Voting Trust Agreement
                            Not applicable.

                    (10) Material Contracts:

                         (10a) Change-In-Control Protective Agreement between 
                               Mahoning National Bancorp, Inc., and Norman E. 
                               Benden, Jr. - Treasurer (Mahoning National 
                               Bancorp, Inc.), Senior Vice President and Chief 
                               Financial Officer (Mahoning National Bank of 
                               Youngstown), filed with the
<PAGE>   13

Mahoning National Bancorp, Inc.
Form 10-K

                                    Registrant's Form 10-Q dated June 30, 1997,
                                    is incorporated herein by reference.

                           (10b)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Richard E. Davies - Secretary (Mahoning
                                    National Bancorp, Inc.), Senior Vice
                                    President and Cashier (Mahoning National
                                    Bank of Youngstown), filed with the
                                    Registrant's Form 10-Q dated June 30, 1997,
                                    is incorporated herein by reference.

                           (10c)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Parker T. McHenry - Vice President (Mahoning
                                    National Bancorp, Inc.), Executive Vice
                                    President (Mahoning National Bank of
                                    Youngstown), filed with the Registrant's
                                    Form 10-Q dated June 30, 1997, is
                                    incorporated herein by reference.

                           (10d)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Gregory L. Ridler - Chairman of the Board,
                                    President and Chief Executive Officer
                                    (Mahoning National Bancorp, Inc.), President
                                    and Chief Executive Officer (Mahoning
                                    National Bank of Youngstown), filed with the
                                    Registrant's Form 10-Q dated June 30, 1997,
                                    is incorporated herein by reference.

                           (10e)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Karen R. DeSalvo - Assistant Vice President
                                    - Marketing (Mahoning National Bank of
                                    Youngstown), filed with the Registrant's
                                    Form 10-Q dated June 30, 1997, is
                                    incorporated herein by reference.

                           (10f)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Frank Hierro - Senior Vice President
                                    (Mahoning National Bank of Youngstown),
                                    filed with the Registrant's Form 10-Q dated
                                    June 30, 1997, is incorporated herein by
                                    reference.
<PAGE>   14

Mahoning National Bancorp, Inc.
Form 10-K

                           (10g)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Dexter Hollen - Vice President and
                                    Compliance Officer (Mahoning National Bank
                                    of Youngstown), filed with the Registrant's
                                    Form 10-Q dated June 30, 1997, is
                                    incorporated herein by reference.

                           (10h)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    John R. Lewis - Senior Vice President
                                    (Mahoning National Bank of Youngstown),
                                    filed with the Registrant's Form 10-Q dated
                                    June 30, 1997, is incorporated herein by
                                    reference.

                           (10i)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    J. David Sabine - Senior Vice President and
                                    Senior Trust Officer (Mahoning National Bank
                                    of Youngstown), filed with the Registrant's
                                    Form 10-Q dated June 30, 1997, is
                                    incorporated herein by reference.

                           (10j)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    David E. Westerburg - Senior Vice President
                                    (Mahoning National Bank of Youngstown),
                                    filed with the Registrant's Form 10-Q dated
                                    June 30, 1997, is incorporated herein by
                                    reference.

                           (10k)    Change-In-Control Protective Agreement
                                    between Mahoning National Bancorp, Inc., and
                                    Donna J. Mowrey - Assistant Vice President
                                    Human Resources (Mahoning National Bank of
                                    Youngstown), included in this form as
                                    Exhibit 10(k), is incorporated herein by
                                    reference.

                           (10l)    Supplemental Executive Retirement Plan
                                    between Mahoning National Bank of Youngstown
                                    and Gregory L. Ridler, originally filed with
                                    the Registrant's Form 10-K dated December
                                    31, 1995, was amended and refiled with the
                                    Registrant's Form 10-Q dated June 30, 1997,
                                    and is incorporated herein by reference.
<PAGE>   15

Mahoning National Bancorp, Inc.
Form 10-K

                           (10m)    Split Dollar Life Insurance Plan between
                                    Mahoning National Bank and Gregory L. Ridler
                                    filed with the Registrant's Form 10-Q dated
                                    June 30, 1997, is incorporated herein by
                                    reference.

                           (10n)    Executive Phantom Stock Bonus Plan between
                                    The Mahoning National Bank of Youngstown and
                                    Norman E. Benden, Jr., filed with the
                                    Registrant's Form 10-Q dated September 30,
                                    1997, is incorporated herein by reference.

                           (10o)    Executive Phantom Stock Bonus Plan between
                                    The Mahoning National Bank of Youngstown and
                                    Frank Hierro, filed with the Registrant's
                                    Form 10-Q dated September 30, 1997, is
                                    incorporated herein by reference.

                           (10p)    Executive Phantom Stock Bonus Plan between
                                    The Mahoning National Bank of Youngstown and
                                    Gregory L. Ridler, filed with the
                                    Registrant's Form 10-Q dated September 30,
                                    1997, is incorporated herein by reference.

                           (10q)    Executive Phantom Stock Bonus Plan between
                                    The Mahoning National Bank of Youngstown and
                                    David E. Westerburg, filed with the
                                    Registrant's Form 10-Q dated September 30,
                                    1997, is incorporated herein by reference.

                           (10r)    Executive Deferred Cash Bonus Plan between
                                    The Mahoning National Bank of Youngstown and
                                    Parker T. McHenry, filed with the
                                    Registrant's Form 10-Q dated September 30,
                                    1997, is incorporated herein by reference.

                           (11)     Statement Regarding Computation of Per Share
                                    Earnings.

                                    The necessary information can be found under
                                    Note A-12 of the Notes to Consolidated
                                    Financial Statements on page 19 of the 1997
                                    Annual Report to Shareholders, included in
                                    this Form 10-K as Exhibit 13, incorporated
                                    herein by reference.
<PAGE>   16

Mahoning National Bancorp, Inc.
Form 10-K

                           (12)     Statement Regarding Computation of Ratios.
                                        Not applicable.

                           (13)     1997 Annual Report to Shareholders.

                           (16)     Letter Regarding Change in Certifying
                                    Accountant.

                                        Refer to Form 8-K, dated May 13, 1996,
                                        Change in Registrants Certifying 
                                        Accountant, incorporated herein by 
                                        reference.

                           (18)     Letter Regarding Change in Accounting
                                    Principles
                                        Not applicable.

                           (21)     Subsidiaries of the Registrant.

                           (22)     Published Report Regarding Matters Submitted
                                    to Vote of Security Holders. Not applicable.

                           (23)     Consents of Experts and Counsel.
                                        Not applicable.

                           (24)     Power of Attorney. Not applicable.

                           (27)     Financial Data Schedule.

                           (28)     Information from Reports Furnished to State
                                    Insurance Regulatory Authorities. Not
                                    applicable.

                           (99)     Additional Exhibits.

                                (a)      Report of Independent Certified
                                         Public Accountants. Predecessor
                                         auditors report for the year ended
                                         December 31, 1995.

                                (b)      The Registrant's Notice of Annual
                                         Meeting and Proxy Statement dated
                                         March 17, 1998.


<PAGE>   17

                                   SIGNATURES

Pursuant to the requirement of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the Registrant has duly caused this report to be signed on its
behalf by the undersigned, thereunto duly authorized on the 17th day of March,
1998.

                  MAHONING NATIONAL BANCORP, INC.
                  (Registrant)


                  /s/ Gregory L. Ridler
                  -------------------------------------
                  GREGORY L. RIDLER
                  President
                  (Principal Executive Officer)

Pursuant to the requirements of the Securities Exchange Act of 1934, this report
has been signed below by the following persons on behalf of the Registrant and
in the capacities indicated on the 17th day of March, 1998.
<TABLE>
<S>                                     <C>
/s/ Norman E. Benden, Jr.                   /s/ Gregory L. Ridler
-----------------------------------         --------------------------------------
Norman E. Benden, Jr. - Treasurer           Gregory L. Ridler
(Principal Financial and                    Chairman of the Board,
 Accounting Officer)                        President and Chief Executive Officer

/s/ Frank A. Kramer                         /s/ Warren P. Williamson, III
-----------------------------------         --------------------------------------
Frank A. Kramer - Director                  Warren P. Williamson, III- Director

/s/ Daniel B. Roth                          /s/ Charles J. McCrudden, Jr.
-----------------------------------         --------------------------------------
Daniel B. Roth - Director                   Charles J. McCrudden, Jr.- Director
</TABLE>


<PAGE>   18


Mahoning National Bancorp, Inc.
Form 10-K

                                  EXHIBIT INDEX

Exhibit
Number

10(k)    Change-In-Control Protective Agreement-Donna J. Mowrey

13       1997 Annual Report to Shareholders

21       Subsidiaries of the Registrant

27       Financial Data Schedule

99(a)    Report of Independent Certified Public Accountants. Predecessor
         Auditors Report for the year ended December 31, 1995.

99(b)    Registrant's Notice of Annual Meeting and Proxy Statement dated March
         17, 1998