We evaluated the efficacy and tolerability of mociobemide, a new reversibie MAOI in 30 patients with depression. The patients were evaiuated dinically, and HRSD and SDS scores were obtained on days 0, 7, 15, 30, and 45. In terms of mean HRSD and SDS total scores, improvement tended to begin on 15th day. Efficacy was judged to be 'very good’ or 'good’ in 29 of 30 patients at the end of the treatment. Daily mean effective dosage of the drug was 450+118 mg. Insomnia occurred in two patients. Hypomania was another adverse effect which was observed in one patient.