<PAGE>

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM 10-Q/A

(Mark One)

[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
     ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED JUNE 30, 1999

                           OR

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

     FOR THE TRANSITION PERIOD FROM _________ TO __________.

                      COMMISSION FILE NUMBER 0-22743


                     VISTA MEDICAL TECHNOLOGIES, INC.
          (Exact name of registrant as specified in its charter)


         DELAWARE                                    94-3184035
(State or other jurisdiction of                   (I.R.S. Employer
incorporation or organization)                   Identification No.)

                          5451 AVENIDA ENCINAS, SUITE A
                               CARLSBAD, CA 92008
                   (Address of principal executive offices)
                                (760) 603-9120
               (Registrant's phone number, including area code)


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:

                        (1)      YES [X]        NO [   ]
                        (2)      YES [X]        NO [   ]

As of August 12, 1999 there were 13,695,684 shares of $.01 par value common
stock outstanding.

                                       1
<PAGE>



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.

                                   VISTA MEDICAL TECHNOLOGIES, INC.


Date:   SEPTEMBER 7, 1999          /S/ JOHN R. LYON
        -------------------        -------------------------
                                   John R. Lyon
                                   President, Chief Executive Officer and
                                   Director


Date:   SEPTEMBER 7, 1999          /S/ ROBERT J. DE VAERE
        -------------------        -------------------------
                                   Robert J. De Vaere
                                   Vice President of Finance & Administration
                                   & Chief Financial Officer
                                   (Principal financial and accounting officer)



                                       2
<PAGE>

Item 5.   Not Applicable

Item 6.   Exhibits and Reports on Form 8-K

A)      Exhibits

       *10.1 Fifth Amendment to Lease Dated April 30, 1999

        10.2 Sofamor Danek letter Amendment dated April 19, 1999

       *11.1 Statement Regarding Computation of Per Share Earnings

       *27.1 Financial Data Schedule

B)      Reports on Form 8-K

        No reports on Form 8-K were filed by the Company during the three
        months ended June 30, 1999.

* Previously filed.

                                       3