AMENDMENT TO

                                    FORM 10-Q

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549



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




FOR QUARTER ENDED                                        COMMISSION FILE NUMBER
   JUNE 30, 1998                                                 0-24630





                           MAHASKA INVESTMENT COMPANY
             (Exact Name of Registrant as Specified in its Charter)




           IOWA                                          42-1003699
(State of Incorporation)                   (I.R.S. Employer Identification No.)



                  222 First Avenue East, Oskaloosa, Iowa 52577

                         Telephone Number (515) 673-8448






Indicate by check mark whether the registrant (1) has filed all reports required
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       
 
As of August 6, 1998, there were 3,651,842 shares of common stock $5 par value
outstanding.

This amendment is being sent to include exhibits which are omitted from the June
30, 1998 Form 10Q of Mahaska Investment Company which was filed August 14, 1998.
The attached  Exhibit 10.5.2 was  inadvertently  omitted from the Form 10Q filed
August 14, 1998.  The attached  Exhibit 27 - Financial  Data Schedule was timely
submitted on August 14, 1998 in a separate filing due to  difficulties  with the
electronic filing system.  This amendment will unite the Financial Data Schedule
with the main text of the Form 10Q.

                                   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.



                                        MAHASKA INVESTMENT COMPANY
                                        (Registrant)



August 18, 1998                         /s/ Charles S. Howard              
Dated                                   Charles S. Howard
                                        President



August 18, 1998                         /s/ David A. Meinert               
Dated                                   David A. Meinert
                                        Executive Vice President and
                                        Chief Financial Officer
                                        (Principal Accounting Officer)



                                 Exhibit 10.5.2

                           MAHASKA INVESTMENT COMPANY
                      FOURTH AMENDMENT TO CREDIT AGREEMENT



Harris Trust and Savings Bank
Chicago, Illinois

Ladies and Gentlemen:

     Reference  is hereby  made to that  certain  Credit  Agreement  dated as of
January 31, 1996, as amended (the "Credit Agreement"),  between the undersigned,
Mahaska Investment Company,  an Iowa corporation (the "Borrower"),  and you (the
"Bank").  All capitalized  terms used herein without  definition  shall have the
same meanings herein as such terms have in the Credit Agreement.

     The Borrower has  requested  that the Bank extend the  Termination  Date to
June 30, 1999, and make certain other  amendments to the Credit  Agreement,  and
the Bank is  willing to do so under the terms and  conditions  set forth in this
agreement (herein, the "Amendment").

1.       AMENDMENTS.

     Subject  to the  satisfaction  of the  conditions  precedent  set  forth in
Section 2 below, the Credit Agreement shall be and hereby is amended as follows:

     1.1 The interest  rate payable  under  Section 2.1 of the Credit  Agreement
shall be reduced and, accordingly,  Section 2.1 of the Credit Agreement shall be
amended by deleting the phrase "at the rate per annum  determined by subtracting
(but not below  zero) 1/4 of 1% per annum from the Prime Rate as in effect  from
time to time"  appearing in the third and fourth lines thereof and inserting the
phrase "at the rate per annum determined by subtracting (but not below zero) 3/8
of 1% per  annum  from the Prime  Rate as in  effect  from time to time" in lieu
thereof.

     1.2 The  definition  of  "Termination  Date"  appearing in Section 4 of the
Credit  Agreement  shall be amended  by  deleting  the date "June 30,  1998" and
inserting the date "June 30, 1999" in lieu thereof.

     1.3 Section 8.1(k) of the Credit Agreement shall be amended and restated in
its entirety to read as follows:

     "(k) Charles  Howard shall at any time and for any reason  ceases to be the
Chairman,  President  and Chief  Executive  Officer of the Borrower or otherwise
ceases to be actively involved in the management of the Borrower; or"

2.       CONDITIONS PRECEDENT.

     The  effectiveness  of this Amendment is subject to the satisfaction of all
of the following conditions precedent:

     (a) The  Borrower  and the Bank  shall have  executed  and  delivered  this
Amendment.

     (b) Legal matters  incident to the execution and delivery of this Amendment
shall be satisfactory to the Bank and its counsel.

3.       REPRESENTATIONS.

     In order to induce the Bank to execute  and  deliver  this  Amendment,  the
Borrower  hereby  represents  to  the  Bank  that  as of  the  date  hereof  the
representations  and warranties  set forth in Section 5 of the Credit  Agreement
are and shall be and remain true and correct  (except  that the  representations
contained  in Section 5.5 shall be deemed to refer to the most recent  financial
statements  of the  Borrower  delivered to the Bank) and the Borrower is in full
compliance  with all of the terms and conditions of the Credit  Agreement and no
Default or Event of Default  has  occurred  and is  continuing  under the Credit
Agreement or shall result after giving effect to this Amendment.

4.       MISCELLANEOUS.

     (a) Except as  specifically  amended  herein,  the Credit  Agreement  shall
continue  in full  force  and  effect in  accordance  with its  original  terms.
Reference to this specific  Amendment need not be made in the Credit  Agreement,
the Note, or any other instrument or document executed in connection  therewith,
or in any  certificate,  letter or  communication  issued or made pursuant to or
with respect to the Credit Agreement,  any reference in any of such items to the
Credit  Agreement being  sufficient to refer to the Credit  Agreement as amended
hereby.

     (b) The  Borrower  agrees to pay on demand  all  costs and  expenses  of or
incurred by the Bank in connection with the negotiation,  preparation, execution
and delivery of this  Amendment,  including the fees and expenses of counsel for
the Bank.

     (c) This  Amendment may be executed in any number of  counterparts,  and by
the different  parties on different  counterpart  signature  pages, all of which
taken together shall  constitute one and the same agreement.  Any of the parties
hereto may execute this  Amendment by signing any such  counterpart  and each of
such  counterparts  shall for all  purposes  be deemed to be an  original.  This
Amendment shall be governed by the internal laws of the State of Illinois.

                           [Signature Page to Follow]
 

     This Fourth Amendment to Credit Agreement is dated effective as of June 30,
1998.

                                            MAHASKA INVESTMENT COMPANY


                                          By /s/ David A. Meinert
                                            Its Executive Vice President& CFO
 

     Accepted  and agreed to in  Chicago,  Illinois as of the date and year last
above written.

                                            HARRIS TRUST AND SAVINGS BANK


                                          By /s/ Patrick A. Horne
                                            Its Vice President