The purpose of this paper is to examine the factors that influence treatment response and outcome in 39 patients with bulimia nervosa who were assessed during the course of 8 weeks of cognitive-behavioral therapy, and after an 8-week and 1-year follow-up period. The patients' progress was assessed using data gathered from clinical examination, structured interviews, and self-rating scales. Patients who had a poor clinical response at the end of treatment had greater pretreatment symptom severity, lower body mass index, and were more likely to have personality disorders. Poor response after 1 year was associated with personality disorder, pretreatment symptom severity, and longer duration of illness. Patients without these poor prognostic indicators are more likely to respond to brief psychoeducational interventions. Patients with poor prognostic indicators are more suited to intensive psychological, pharmacologic, and experimental treatment approaches. © 1993 by John Wiley & Sons, Inc.