Despite growing evidence that child welfare youth are at increased risk for juvenile delinquency, little is known about gender-specific processes and effective treatment programs for girls. Multidimensional Treatment Foster Care (MTFC), an empirically validated intervention for child welfare and juvenile justice populations, has demonstrated efficacy in reducing arrest rates in delinquent boys and girls. In this study, the efficacy of MTFC on school attendance and homework completion was examined in juvenile justice girls who were referred to out-of-home care (N = 81). Results from this randomized intervention trial suggest that MTFC was more effective than group care in increasing girls' school attendance and homework completion while in treatment and at 12 months post-baseline. In addition, the previously reported effect of MTFC on reducing girls' days in locked settings was mediated by homework completion while girls were enrolled in the intervention setting. Implications for policy and practice are described. (Contains 2 tables and 1 figure.)