<Page>


    ------------------------------------------------------------------------


                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549





                                    FORM 6-K

                            REPORT OF FOREIGN ISSUER

    PURSUANT TO RULE 13a-16 OR 15d-16 OF THE SECURITIES EXCHANGE ACT OF 1934

                    FILING NO. 1 FOR THE MONTH OF JULY, 2002




                              Visible Genetics Inc.
                              ---------------------
                           (Exact name of Registrant)

             700 Bay Street, Suite 1000, Toronto ON, Canada M5G 1Z6
             ------------------------------------------------------
                    (Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports
under cover Form 20-F or Form 40-F

                          Form 20-F  X    Form 40-F
                                    ---             ---

Indicate by check mark whether the registrant by furnishing the information
contained in this Form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

                                Yes       No  X
                                    ---      ---



    ------------------------------------------------------------------------


<Page>




                              VISIBLE GENETICS INC.

      On July 8, 2002, Visible Genetics Inc. ("we" or the "Company") reported
that we expect our 2002 second quarter revenues to be in the range of $4.5
million to $4.7 million. North American sales of the Company's HIV genotyping
kit, launched in the U.S. late in the fourth quarter of 2001, led the sales
increase with second quarter sales increasing by approximately 25% over the
level of the first quarter of 2002. North American HIV genotyping kit sales
increased approximately 77% over the same period in 2001. In addition, European
HIV genotyping kit sales increased approximately 20% from the first quarter to
the second quarter. (All amounts are in United States dollars.)

      We expect to report that second quarter 2002 worldwide revenues for gene
kits and consumables were in the range of $4.2 million to $4.3 million, up
approximately 19% from the levels of the first quarter of 2002. Diagnostic
product revenues represented approximately 92% of total revenues in the second
quarter versus 83% in the first quarter of 2002, and 74% in the second quarter
of 2001. Non-diagnostic revenue consisted primarily of instrument sales, mainly
in the Far East. Total revenues for the second quarter of 2002 are expected to
increase approximately 7% from the revenues in the first quarter of 2002 and
increase approximately 18% from the second quarter of 2001. For the six months
ended June 30, 2002, the Company expects to report total revenues of $8.9
million to $9.1 million, an increase of approximately 20% from the comparable
period in 2001.

      THIS FORM 6-K CONTAINS FORWARD-LOOKING STATEMENTS WITHIN THE MEANING OF
THE "SAFE HARBOR" PROVISIONS OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF
1995. A VARIETY OF FACTORS COULD CAUSE ACTUAL RESULTS TO DIFFER MATERIALLY FROM
THE ANTICIPATED RESULTS OR OTHER EXPECTATIONS EXPRESSED IN THESE FORWARD LOOKING
STATEMENTS. THE RISKS AND UNCERTAINTIES THAT MAY AFFECT THE OPERATIONS,
PERFORMANCE, DEVELOPMENT AND RESULTS OF THE COMPANY INCLUDE BUT ARE NOT LIMITED
TO: WHETHER WE SELL OUR COMPANY OR ENTER INTO ANOTHER STRATEGIC TRANSACTION; THE
TIMING OF OUR FUTURE CAPITAL NEEDS AND/OR INABILITY TO RAISE ADDITIONAL CAPITAL
WHEN NEEDED; UNCERTAINTY OF ACCEPTANCE OF GENOTYPING IN GENERAL, AND OF OUR
PRODUCTS, IN PARTICULAR IN THE CLINICAL DIAGNOSTIC MARKET; DESIRE OF THE FDA TO
TAKE ENFORCEMENT ACTION TO RESTRICT THE USE OF HOME BREW GENOTYPING TESTS TO
PROVIDE DRUG RESISTANCE REPORTS AND TESTS TO PHYSICIANS AND OTHER HEALTH CARE
PROVIDERS; REFUSAL OF INSURANCE COMPANIES AND OTHER THIRD PARTY PAYORS TO
REIMBURSE PATIENTS OR PHYSICIANS FOR OUR PRODUCTS; PROBLEMS THAT WE MAY FACE IN
OUR ABILITY TO SELL OUR HEPATITIS C GENOTYPING KIT TO THE CLINICAL RESEARCH
MARKET; PROBLEMS THAT WE MAY FACE IN MANUFACTURING, MARKETING AND DISTRIBUTING
OUR PRODUCTS; DELAYS WHICH MAY OCCUR IN MAKING OUR ATLANTA MANUFACTURING
FACILITY FULLY OPERATIONAL; DELAYS IN OBTAINING OR OUR INABILITY TO OBTAIN
APPROVAL BY THE FDA FOR CHANGES MADE TO FDA-APPROVED PRODUCTS; DELAYS IN
OBTAINING OR OUR INABILITY TO OBTAIN APPROVAL BY CERTAIN FOREIGN REGULATORY
AUTHORITIES FOR OUR HIV OPENGENE SYSTEM AND CERTAIN OTHER PRODUCTS; DELAYS IN
OBTAINING OR OUR INABILITY TO OBTAIN FDA APPROVAL FOR CERTAIN OF OUR FUTURE
PRODUCTS; PROBLEMS WE MAY FACE WITH FUTURE CLINICAL TRIALS; PROBLEMS IN
ACQUIRING AND PROTECTING INTELLECTUAL PROPERTY IMPORTANT TO OUR BUSINESS THROUGH
PATENTS, LICENSES AND OTHER ARRANGEMENTS; OUR ABILITY TO SUCCESSFULLY DEFEND
CLAIMS THAT OUR PRODUCTS MAY INFRINGE THE INTELLECTUAL PROPERTY RIGHTS OF
OTHERS; PROBLEMS WITH IMPORTANT SUPPLIERS AND BUSINESS PARTNERS; DELAYS IN
DEVELOPING OR THE FAILURE TO DEVELOP NEW PRODUCTS AND ENHANCED VERSIONS OF
EXISTING PRODUCTS; AND OTHER ISSUES DETAILED FROM TIME TO TIME IN THE COMPANY'S
SEC FILINGS. THESE FORWARD LOOKING STATEMENTS SPEAK ONLY AS OF THE DATE HEREOF.
VISIBLE GENETICS DISCLAIMS ANY INTENT OR OBLIGATION TO UPDATE THESE FORWARD
LOOKING STATEMENTS.


<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.

                                          VISIBLE GENETICS INC.


Date: July 8, 2002                        By: /s/ Thomas J. Clarke
                                              --------------------
                                              Name: Thomas J. Clarke
                                              Title: Chief Financial Officer