The objective of this report is to identify psychosocial correlates of unprotected anal sex among attendants at a support group for HIV-negative gay and bisexual men. Presupport group measures were given to 55 self-identified urban HIV-negative gay and bisexual men in a high-incidence HIV location (San Francisco) attending a 10-week, weekly, 2-hour support group at the University of California at San Francisco (UCSF) AIDS Health Project. Participants completed self-administered questionnaires that included measures of perceived risk, condom self-efficacy, social support, HIV knowledge, and depression. At baseline, 25% of the participants reported unprotected anal sex (receptive or insertive) in the two months preceding enrollment. This finding was independent of whether the participant was single or involved in a relationship, and whether or not the participant's partner was infected with HIV. Participants were found to generally have very high AIDS knowledge and low depression scores. In bivariate analysis, unprotected anal sex was associated with low condom self-efficacy, low AIDS knowledge, dissatisfaction with social support, and lower commitment to safer sex. In multivariate analysis, unprotected anal sex was independently associated with low condom self-efficacy (p = .006), and low AIDS knowledge (p = .007). Additionally, a borderline significant result was found when measuring satisfaction with social support (p =.085). No association was found between depression scores and unprotected sexual activity.