In 2 studies, beliefs supporting the use of violence moderated the association between normative masculine activities and aggressive behavior (Study 1) and normative masculine attitudes and aggressive and homophobic behavior (Study 2) among adolescent boys. These beliefs also moderated the association between normative masculine activities and homophobic behavior among adolescent girls. Consistent with social information processing models, beliefs about the appropriateness and effectiveness of violence predicted aggressive behavior for boys and girls, including bullying, fighting, and relational aggression. Furthermore, the association between masculine norms and aggressive behavior and homophobic behavior was partly dependent on holding these beliefs among boys. Continued research is needed to identify other beliefs that may distinguish different expressions of masculinities and their association with other attitudes and behaviors. Within the broader aggression and homophobia literature among adolescents there is a need to include the study of gender norms, while recognizing the complexity with which these factors are associated. (Contains 6 figures and 6 tables.)