The purpose of this study was to empirically evaluate hypothesized risk factors for the perpetration of antigay aggression. Specifically, the independent and interactive effects of endorsement of hegemonic male role norms and peer group relational factors (i.e., closeness) were examined as individual and situational risk factors for antigay aggression, within the framework of the General Aggression Model (GAM). Dyads of friends were recruited for participation in the study. Participants completed questionnaires that included measures of hegemonic masculinity and friendship closeness. The dyads of friends then viewed a video depicting male-male intimacy and competed in the TAP together against a fictitious gay opponent. Results showed that endorsement of the toughness norm was associated with both higher average shock intensity and proportion of highest shock selected. However, neither measure of relationship closeness served as a significant moderator of this relation.