Family-based therapy (FBT) is currently the most evidence-based treatment for adolescents with eating disorders. The aim of this review is to summarize previous research results regarding the efficacy of the manualized FBT according to Lock and Le Grange and to report on moderators and mediators. In 5 randomized controlled trials (RCTs) in anorexia nervosa (N=560) remission rates were between 21.2-42% at end of treatment, between 21.8-40% at 6-month follow-up, and between 29-49% at 12-month follow-up. Remission rates for patients with bulimia nervosa (2 RCTs, N=210) were 39%, 29-44% and 49% respectively. It would be desirable to replicate these results through independent working groups and in other countries. In addition, it would also be important to evaluate FBT in comparison to cognitive behavioral therapy and psychodynamic therapy, and to further explore strategies for non-responders.