Although cognitive behavioral treatment is the treatment of choice in bulimia nervosa, patients' response is variable. A minority of patients do not respond at all and some never engage in treatment. This paper concerns the latter group. A case series of six such patients with whom treatment could not be initiated is compared with a group who received a full course of treatment. The group with whom treatment could not begin were found to have a longer history of disorder, to report excessive laxative abuse, to have more severe depressed mood and a greater dissatisfaction with their body weight. In addition, they were more likely to have abused psychoactive substances, engaged in episodes of self-harm, and have a lower self-esteem. They were also more likely to be diagnosed as having borderline personality disorder. Patients presenting with the wide range of difficulties characteristic of this group require a more intensive form of treatment than standard outpatient cognitive behavior therapy.