Three groups of San Francisco bar patrons (heterosexual men, heterosexual women, and gay men) were compared on four sexual risk reduction strategies for AIDS: safer sex practices (particularly adoption of the use of condoms), reducing the number of sexual partners, taking the HIV antibody test, and determining the characteristics of a potential sexual partner. Heterosexuals reported fewer sex partners and were more likely than gay men to interview potential partners. Gay men were more likely to use condoms and the HIV antibody test than their heterosexual counterparts. These findings encourage the design of interventions that take advantage of shaping and reinforcing strategies already in use in each group, and suggest when it is necessary to teach new strategies.