Based on the Theory of Reasoned Action, this study evaluated a "socialization" model linking girls' peer crowd affiliations (e.g., Jocks, Populars) with their own weight concern, perceived peer weight norms, and weight control behaviors. An alternative "selection" model was also evaluated. Girls (N = 236; M age = 15.95 years) from diverse ethnic backgrounds completed surveys assessing peer crowd affiliation, their own concern with weight, perceptions of peers' concern with weight, and weight control behaviors. Models were evaluated using SEM. The socialization model demonstrated good fit; the alternative selection model did not. Specifically, girls' level of identification with certain peer crowds (Jocks, Burnouts, Alternatives) was associated with girls' reported own concern and perceived peer concern with weight. Additionally, girls' own concern and peer norms were related independently to girls' weight control behaviors. Findings suggest that peer crowds and girls' own and peer weight norms may be important targets of prevention efforts.