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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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                              FORM 10-Q/A (No. 1)

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

                For the quarterly period ended September 30, 1998

                                       OR

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


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                         Commission file number 0-21982

                            DIAMETRICS MEDICAL, INC.
                 Incorporated pursuant to the Laws of Minnesota


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       Internal Revenue Service -- Employer Identification No. 41-1663185

                  2658 Patton Road, Roseville, Minnesota 55113
                                 (612) 639-8035

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

The total number of shares of the registrant's Common Stock, $.01 par value,
outstanding on October 30, 1998, was 23,378,217.


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The undersigned registrant hereby amends Part II, Item 6(a), entitled 
"Exhibits," of its Quarterly Report on Form 10-Q for the quarter ended September
30, 1998 to amend and refile Exhibit 10.1.


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                          PART II - OTHER INFORMATION
 
     Item 6. Exhibits and Reports on Form 8-K

     a. Exhibits

<TABLE>
<CAPTION>
     Exhibit                                                                                  Method
       No.                             Description                                           of Filing
     -------                           -----------                                           ---------
<S>                <C>                                                                    <C>
      10.1*        Distribution Agreement, dated October 1, 1998, between 
                   the Company and Johnson & Johnson Professional, Inc.                   Filed herewith

      10.2**       Put Option and Stock Purchase Agreement, dated October 1, 
                   1998, between the Company and Johnson & Johnson Development 
                   Corporation                                                            

      10.3**       Severance Pay Agreement (in the event of Change of Control) 
                   dated July 31, 1998, between the Company and David T. Giddings         

      10.4**       Form of Severance Pay Agreement (in the event of Change of 
                   Control) dated July 31, 1998, between the Company and its 
                   executive officers                                                     

      10.5**       Form of Severance Pay Agreement (in the event of Termination 
                   Without Cause) dated July 31, 1998, between the Company and 
                   its executive officers                                                 

      27**         Financial Data Schedule                                                

      99**         Cautionary Factors Under the Private Securities Litigation 
                   Reform Act                                                             
</TABLE>


     *    Pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as
          amended, confidential portions of Exhibit 10.1 have been deleted and
          filed separately with the Securities and Exchange Commission pursuant
          to a request for confidential treatment.

    **    Previously filed.

     b. Reports on Form 8-K.

          None

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                            DIAMETRICS MEDICAL, INC.


SIGNATURE

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.



DIAMETRICS MEDICAL, INC.




By: /s/ Laurence L. Betterley
    -----------------------------
    Laurence L. Betterley
    Senior Vice President
    and Chief Financial Officer
    (and Duly Authorized Officer)


Dated: January 5, 1999

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                            DIAMETRICS MEDICAL, INC.
                                 EXHIBIT INDEX

Exhibit
  No.                          Description
-------                        -----------

10.1*    Distribution Agreement, dated October 1, 1998, between the Company and
         Johnson & Johnson Professional, Inc.

10.2**   Put Option and Stock Purchase Agreement, dated October 1, 1998, between
         the Company and Johnson & Johnson Development Corporation

10.3**   Severance Pay Agreement (in the event of Change of Control) dated 
         July 31, 1998, between the Company and David T. Giddings

10.4**   Form of Severance Pay Agreement (in the event of Change of Control) 
         dated July 31, 1998, between the Company and its executive officers

10.5**   Form of Severance Pay Agreement (in the event of Termination Without
         Cause) dated July 31, 1998, between the Company and its executive
         officers

27**     Financial Data Schedule

99**     Cautionary Factors Under the Private Securities Litigation Reform Act

 *    Pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as amended,
      confidential portions of Exhibit 10.1 have been deleted and filed
      separately with the Securities and Exchange Commission pursuant to a
      request for confidential treatment.

**    Previously filed.