This study was conducted to assess the predictors of safe sex practices among a group of college students. Subjects were 261 students attending the evening division of a large urban university campus, 68% of whom were female and 94% of whom reported being heterosexual. The average age of respondents was 26 years. Subjects responded to questions concerning their knowledge about sources of human immunodeficiency virus (HIV) transmission, history of sexual behavior, attitudes toward homosexuality, intravenous drug use, casual sex, Acquired Immune Deficiency Syndrome (AIDS) hysteria, and heterosexual invulnerability to infection. The majority of students knew how HIV was transmitted, but 40.4% responded incorrectly or were unsure about ways in which one cannot be infected. Nine percent of the heterosexual population practiced safer sex although 27% had sexual contact with a high risk group member. A stepwise discriminant analysis using variables hypothesized in the research literature to be associated with practicing safer sex was used to predict group membership. Five predictor variables successfully classified 75% of the grouped cases. The safer sex group was younger, felt less vulnerable to AIDS, was more positive about sexual activity, felt more assured of the actual routes of transmission, and were more critical of intravenous drug users. (Author/NB)