Objective: There is a paucity of evidence-based interventions for anorexia nervosa (AN). An innovative family-based treatment (FBT), developed at the Maudsley Hospital and recently put in manual form, has shown great promise for adolescents with AN. Unlike traditional treatment approaches, which promote sustained autonomy around food, FBT temporarily places the parents in charge of weight restoration. This aim of this open trial was to investigate the feasibility and effectiveness of delivering FBT at a site beyond the treatment's origin and manualization. Method: Twenty adolescents (ages 12-17) with AN or subthreshold AN were treated with up to 1 year of FBT using the published treatment manual. Outcome indices included the percentage of ideal body weight, menstrual status, the Eating Disorder Examination (EDE) subscales scores, and the Children's Depression Rating Scale-Revised score. Results: Of the 20 patients recruited, 15 (75%) completed a full course of treatment. Intent-to-treat analyses showed significant improvement over time in the percentage of ideal body weight (t = -4.46, p = 0.000), menstrual status (p = 0.002), EDE Restraint (z = -3.02, p = 0.003), EDE Eating Concern (z = -2.10, p = 0.04), but not in EDE Shape Concern or Weight Concern subscales or Children's Depression Rating Scale-Revised score. Conclusions: This open trial provides evidence that FBT can be successfully disseminated, replicating the high retention rates and significant improvement in the psychopathology of adolescent AN seen at the original sites. (Contains 1 table and 2 figures.)