This study was undertaken to evaluate the life expectancy of gay and bisexual men in the West End of Vancouver, British Columbia during two time periods. Mortality data for males were obtained for the periods 1990 to 1992 and 1995 to 1997 and population estimates were obtained from the 1991 and 1996 Census. The proportion of the male population over 20 years of age estimated to be gay and bisexual was derived from a random telephone survey. Mortality patterns were assessed by comparing changes in life expectancy at age 20 years between the periods, and by examining the life expectancy lost attributed to HIV/AIDS. Between the periods there was 3.8 +/- 3.4 years increase in life expectancy among gay and bisexual men. At exact age 20 years, life expectancy increased from 37.0 +/- 3.5 years during the period 1990 to 1992 to 40.8 +/- 2.4 years during the period 1995 to 1997. The loss of life expectancy attributed to HIV/AIDS at this age was 13.8 +/- 3.9 during the first period and 9.8 +/- 3.6 years during the second period. This gain is most likely the result of the improved efficacy of antiretroviral therapies.