Reductions in AIDS cases among men who have sex with men (MSM) have been attributed in part to widespread declines in unprotected anal sex since the mid-1980s and use of increasingly effective antiretroviral therapy (ART) since the mid-1990s. Because data about HIV infection incidence are limited, other indicators of transmission risk have been used. In San Francisco, data from annual behavioral surveys among MSM (1994-1997) and from the sexually transmitted disease (STD) surveillance program (1990-1997) were analyzed to characterize changes in HIV risk behaviors of MSM and changes in incidence of male rectal gonorrhea. This report describes the findings of these analyses, which indicate increases in unsafe sexual behavior and increases in rates of rectal gonorrhea among MSM.