One hundred patients, scheduled to receive operations under spinal anesthesia with tetracaine, were premedicated with haloperidol (Serenace, 0. 08mg/kg I.M.) or diasepam (0.3mg/hg LM.) and evaluated for effects of these premedicants in Seoul National University Hoapital. The results were as follows: 1) Haloperidol was superior to diaxepam in poetoperative antianxiety and analgesic effects. 2) Haloperidol and diasepam were equal in their antiemetic effects. 3) Both haloperidol (0. 04 mg/kg) and diaaepam (0. 1mg/kg) as an intravenous bolus were effective for sedation during operation. Patients given haIoperidol, however, were more cooperative to anesthesiologists and surgeons than were those given diazepam.