We evaluated the outcome of the treatment with a retrospective analysis of the weight data recorded in the charts of the patients and the notes of the dietician. Three patients dropped out of group treatment within two sessions. No data were recorded for these patients. For one patient who completed treatment, no data were available retrospectively. Thus, data were analyzed for six patients, all with a diagnosis of schizophrenia (two men and four women; age: mean=37.3 years, SD=14.7). Four patients were treated with clozapine (dose range: 25–250 mg/day) and two with 10 mg/day of olanzapine. Before treatment the mean body mass index was 29.6 kg/m2 (SD=2.5, range=26.6–34.0). After treatment, the body mass indexes ranged from 22.28 to 30.12 kg/m2 with a mean of 25.1 (SD=3.0); the difference between pre-and posttreatment was significant according to a paired t test (t=3.97, df=5, p<0.02). Actual weight loss ranged from 0 to 21 kg. Five of these six patients showed a posttreatment body mass index of less than 25 kg/m2, the upper limit of the recommended range.