Binge Eating Disorder (BED) is one of the most frequent eating disorders in industrialized societies. Reduced serotonin activity has been suggested to trigger some of the cognitive and mood disturbances associated with BN. Therefore, pharmacological treatment of BED is mainly based on the use of selective serotonin reuptake inhibitors, that have proved effective. The biological basis of this disorder has not been completely established yet. The aim of this randomized, controlled trial was to verify the efficacy of sertraline, a selective serotonin reuptake inhibitor, in a group of patients with BED. Twenty female outpatients, with an age range of 24-36 years having BED-binge purging, as defined by the DSM IV, were assigned randomly into two treatment groups; the first group received sertraline 100 mg/day for 12 weeks, the second group received placebo. The study was conducted for 12 weeks with weekly clinical assessments. At the end of the treatment period, the treated patients with sertraline showed a significant reduction in the number of binge eating crisis and purging with respect to the group who received only placebo . Treatment was never interrupted for any emergency reasons. This study confirms that sertraline is well tolerated and effective in reducing binge-eating crisis and purging in patients with bulimia nervosa.