Although research indicates that female offenders demonstrate higher rates of mental health symptoms than male offenders, the lack of data on directly comparable groups of delinquent and community youths has limited this comparison. The current study includes adolescents detained in juvenile detention facilities (girls = 157; boys = 276) or who resided in the community (girls = 193; boys = 242) from four different geographical locales. Results indicate that the relative magnitude of gender differences was greater in detained youths than in community youths, with detained girls exhibiting greater levels of symptomatology than would be predicted on the basis of gender or setting alone. Although it may be self-evident that detained populations exhibit higher levels of externalizing problems than community populations, the present study helps to quantify such differences by using common measures and demographically matched samples and demonstrates that detained versus community differences are larger among girls than among boys.