Men (N = 526) who patronized gay bars in three cities completed measures of sexual behavior covering the previous 3 months and psychological measures theoretically pertinent to AIDS risk. Thirty-seven percent of the sample reported engaging in unprotected anal intercourse, the behavior most strongly associated with transmission of human immunodeficiency virus (HIV) infection. Perceived peer norms concerning the acceptability of safer sex practices, AIDS health locus of control scores, risk behavior knowledge, age, and accuracy of personal risk estimation, but not personal HIV serostatus knowledge, were associated with high-risk and precaution-taking behavior.