This study investigated the association between interpersonal relationships, eating behaviors, and body esteem in a sample of adolescent girls. Participants included 876 girls who completed questionnaires regarding body esteem, eating behavior, peer pressure, and interpersonal relationships. Peer pressure was a strong predictor of eating behavior and body esteem after controlling for interpersonal variables. High externalized self-perceptions, self-reported teasing, and attributions about the importance of weight and shape for popularity and dating were important predictors of both body esteem and eating behavior. Also, girls who were nominated as popular by peers were more likely to engage in disordered eating and have lower body esteem. Results highlight the need for eating disorder prevention at the level of the peer group. Programs should focus on decreasing pressure to be thin, acceptance by peers for attributes other than appearance, and combating weight- and shape-related teasing within the school system.