Little is known about adolescents' perceptions of interpersonal aggression and the role of traditional social attitudes in these perceptions. Sixteen-year-old students (N = 212) of both sexes rated the seriousness of 9 aurally presented scenarios depicting either sexual or nonsexual, physical aggression. Sex of perpetrator and sex of victim were manipulated partly factorially. Students also reported on their own experiences (as perpetrators and victims) of the aggression portrayed, and completed a measure of traditional sex role ideology. Sexual aggression was rated as more serious than nonsexual physical aggression, especially when involving physical force. Girls gave higher seriousness ratings than did boys. Male-to-female aggression was rated as most serious, and male-to-male aggression, least serious. Self-reported perpetrators tended to give lower ratings of seriousness than did victims. Traditional sex-role attitudes were associated with lower rated seriousness but not with reported perpetration or victimization. Multivariate analyses suggested that the effects of traditional sex-role attitudes could largely be subsumed by the effects of other study variables, especially participant sex. The role of attitudes as a direct cause of interpersonal aggression is discussed along with implications for intervention.