PURPOSES: This study examined the relationship between risk behaviors and sexual knowledge, sexual attitudes, and sexual experiences of male high school students. METHOD: A cross-sectional, descriptive study was conducted. Data were collected from 2 male high schools in metropolitan Gwangju. Five hundred forty-eight boys were enrolled in this study. Descriptive statistics, factor analysis, t-test or ANOVA, and Pearson's correlation were used for data analysis. RESULTS: The mean sexual knowledge and sexual experience scores were relatively low, 0.60 out of 1 point, and 0.75 out of 4 points, respectively. Three attitude types of the students were identified: permissible, conservative and pleasure seeking attitude. The score of the permissible type was affected by the subjects' exposure to pornographic material. The score of the conservative type was affected by alcohol consumption and acquaintances with a heterosexual friend. The score of the pleasure seeking type was affected by their exposure to pornographic material, alcohol consumption, smoking, going to a video-room, and acquaintances with a heterosexual friend. There was a negative correlation between the permissible type and sexual knowledge, and a positive correlation between the conservative and pleasure seeking types and sexual experience. CONCLUSION: Male high school students who have been exposed to risk behaviors have a higher likelihood of indulging in sexual activity, and the pleasure seeking type appears to be related to sexual experience. An educational program may be needed to prevent risky behaviors and sexual experiences in male high school students considering their sexual attitude type.