Objective: To evaluate a community-based intervention aimed at the primary prevention of disordered eating among preadolescent girls. Design: Girl Scout troop members were randomized into control and intervention groups. Program feasibility and effect at postintervention and 3-month follow-up were evaluated. Subjects/setting: 226 girls (mean age=10.6 years, standard deviation=0.7) from 24 Girl Scout troops. Intervention: Six 90-minute sessions focusing on media literacy and advocacy skills. Main outcome measures: Evaluation focused on program satisfaction and short-term effect on dieting behaviors, body image attitudes, and media knowledge, attitudes, and habits. Statistical analyses: performed t tests, χ2 tests, and analyses of covariance including troop as a random source of variation. Results: At baseline, 29% of the girls were trying to lose weight. The program had a notable positive influence on media-related attitudes and behaviors including internalization of sociocultural ideals, self-efficacy to impact weight-related social norms, and print media habits. A modest program effect on body-related knowledge and attitudes was apparent at post-intervention (ie, on body size acceptance, puberty knowledge, and perceived weight status) but not at follow-up. Significant changes were not noted for dieting behaviors, but they were in the hypothesized direction. Satisfaction with the program was high among girls, parents, and leaders. Applications/conclusions: It is feasible to use community youth settings, such as the Girl Scouts, to implement interventions to prevent disordered eating behaviors. The program led to positive trends in outcome variables; however, longer and more intensive interventions are needed for lasting changes in body image and dieting behaviors.