Eighty two patients with bulimia nervosa were managed by providing them with supervision in the use of a highly structured cognitive behavioral self-help manual. Their progress was assessed in an open clinical trial. The 67 patients who completed the course of self-help experienced considerable benefit; the frequency of bulimic episodes and self-induced vomiting decreasing by 80% and 79%, respectively. Compared to those who benefited, those who had a poor outcome or dropped out of treatment were more than twice as likely to have had anorexia nervosa in the past and were somewhat more likely to have a personality disorder. Three-quarters of those who persisted with the programme of supervised self-help were followed up a year after commencing treatment. Clinical gains were well maintained: almost two thirds were abstinent with respect to both bulimic episodes and self-induced vomiting. It would seem appropriate that, as part of a stepped care approach to the management of bulimia nervosa, supervised cognitive behavioral self-help should routinely be the first line treatment.