Background: This study examined alcohol consumption and sexually transmitted disease risk behavior as related to prostitute visits and sex partner mix among male Korean university students in 1993 to 1994. Methods: Questionnaires were completed by a representative sample of 1103 university students in Seoul. Lifetime sexually transmitted disease risk behavior was categorized as none, only one, and multiple sexual experiences with prostitutes, whereas risk according to partner mix was classified as no sexual experience with prostitutes, sexual experience with prostitutes only, and with both prostitutes and girlfriends. The proportional odds model was applied to the data. Results: A total of 25.8% of the university students had visited prostitutes–17.6% visited twice or more, and 12.9% had sexual experiences with both prostitutes and girlfriends. Heavier alcohol consumption was significantly related to multiple visits to prostitutes (odds ratio = 1.71) and to sexual experiences with both prostitutes and girlfriends (odds ratio = 2.30). Conclusions: In this first systematic study of the association between alcohol consumption and sexual experiences among Korean male university students, alcohol use was associated with risky sexual behaviors, and with first and most recent sexual experience with prostitutes, supporting our hypotheses.