The authors report on the development of a manual for treating adolescents with anorexia nervosa modeled on a family-based intervention originating at the Maudsley Hospital in London. The manual provides the first detailed account of a clinical approach shown to be consistently efficacious in randomized clinical trials for this disorder. Manualized family therapy appears to be acceptable to therapists, patients, and families. Preliminary outcomes are comparable to what would be expected in clinically supervised sessions. These results suggest that through the use of this manual a valuable treatment approach can now be tested more broadly in controlled and uncontrolled settings.