The purpose of this paper was to describe and appraise the research evidence on the effects of acute alcohol intoxication and sexual arousal on sexual risk behaviors in men who have sex with men (MSM) and to examine its implications for design of HIV prevention interventions that target MSM. Toward that end, the paper begins with a discussion of research on sexual arousal in men and alcohol and their acute effects on sexual behaviors. This is followed by a review of empirical evidence on the combined acute effects of alcohol and sexual arousal in heterosexual men (the large majority of studies) and then in MSM. The empirical evidence and related theoretical developments then are integrated to derive implications for developing effective HIV prevention interventions that target MSM.