OBJECTIVES: We describe the prevalence of risk behaviors at baseline among men who have sex with men (MSM) who were enrolled in a randomized behavioral intervention trial conducted in 6 US cities. METHODS: Data analyses involved MSM who were negative for HIV antibodies and who reported having engaged in anal sex with 1 or more partners in the previous year. RESULTS: Among 4295 men, 48.0% and 54.9%, respectively, reported unprotected receptive and insertive anal sex in the previous 6 months. Unprotected sex was significantly more likely with 1 primary partner or multiple partners than with 1 nonprimary partner. Drug and alcohol use were significantly associated with unprotected anal sex. CONCLUSIONS: Our findings support the continued need for effective intervention strategies for MSM that address relationship status, serostatus of partners, and drug and alcohol use.