The current study investigated the relationship between attitudes towards sexual aggression, perceived peer norms about sexual aggression and sexually aggressive behaviour. Most of the past research on attitudes towards sexual aggression has used a broad definition of attitudes that does not seem to assess evaluation. Additionally, few studies have examined the combined role of evaluative attitudes and perceived peer norms in sexually aggressive behaviour. The current study found that attitudes, but not peer norms, were consistently associated with sexually aggressive behaviour. Attitudes also mediated the relationship between peer norms and sexual aggression. Lastly, the relationship between attitudes and past sexual aggression depended on norms, and participants with both highly positive attitudes and peer norms about sexual aggression reported the highest levels of sexually aggressive behaviour. These results extend previous research and provide important information regarding the relationship between attitudes, peer norms, and sexual aggression.