The broader context of relational aggression in adolescent romantic relationships was assessed by considering the ways such aggression emerged from prior experiences of peer pressure and was linked to concurrent difficulties in psychosocial functioning. Longitudinal, multi-reporter data were obtained from 97 adolescents and their best friends at age 15 and from adolescents and their romantic partners at age 18. Teens' relational aggression and romantic partners' victimization were predicted from levels of best friends' pressuring behaviors toward teens in an observed interaction as well as from best friends' ratings of how much pressure teens experienced from their peer group. Romantic partner relational aggression and teen victimization were predicted by pressure from teens' peer group only. Adolescents' romantic relational aggression and victimization were also associated with elevated levels of depressive symptoms and increased alcohol use. Results are discussed in terms of the connection of relational aggression in romantic relationships to the broader task of establishing autonomy with peers in psychosocial development.