Socialization among aggressive friends is believed to play a critical role in the development of aggressive behavior. This study examined the moderating effect of norm salience in the classroom on the association between reciprocal friends' and children's own physical, relational, and general aggression. A total of 713 children (M = 10.32 years, SD = 0.99) in grades 4 to 6 completed a peer nomination inventory in the fall and spring of the same academic year. Norm salience was operationalized as the class- and sex-specific correlation between each form of aggression and social preference. Norm salience moderated relational aggression socialization among friends only for highly relationally aggressive girls. Specifically, socialization was exacerbated when norm salience was favorable and attenuated when norm salience was unfavorable, suggesting that highly relationally aggressive girls may possess skills allowing them to adapt to the social context in which they and their friends interact. In contrast, boys' general aggression socialization was exacerbated when norm salience was neutral or unfavorable, suggesting that boys who affiliate with aggressive friends may be more susceptible to aggressive friends' influence in general and especially in the context of potential peer rejection. No moderating effect of norm salience was found in regards to physical aggression socialization. Results suggest that interventions aimed at changing acceptability of aggression in the classroom may only be effective in specific subgroups of aggressive youth.