A 24-month naturalistic, prospective longitudinal followup study was conducted on 33 patients with anorexia nervosa who had participated in an intensive, multidisciplinary inpatient treatment program and were receiving fluoxetine as part of their continuing treatment regimen. Data on course, outcome, and treatment exposure in this cohort were obtained using standardized, comprehensive interviews administered at 6-month intervals after hospital discharge. Longitudinal course data for these patients were compared with data for matched historical controls who had received identical inpatient and followup treatment but without adjunctive fluoxetine. Analyses failed to show that fluoxetine had a significant effect on the cumulative probability of remaining at target weight during the followup period, the risk of sustained weight loss, or other clinical measures of outcome. Thus, adjunctive treatment with fluoxetine may not have additive long-term therapeutic benefit when measured against the effects of sustained and intensive followup treatment.