Background: Postoperative nausea and vomiting (PONV) is one of the major causes that delays patients discharge in outpatient surgery. A transdermal scopolamine patch (TSP) is effective in preventing PONY and covers PONY for a long duration (72 hr) even after discharge. Therefore, we evaluated PONY using TSP on outpatient conization cases. Methods: Forty four patients scheduled for a conization due to cervical intraepithelial neoplasm were randomly divided into two groups. A Band-Aid)-like patch containing either scopolamine (22 patients in TSP group) or a placebo (22 patient in placebo group) was placed either mastoid area at the night before surgery. Anesthesia was induced with fentanyl (50 or 100 ) and thiopental (375 mg/kg) and maintained with enflurane (1 vol%) and nitrous oxide (60%) in oxygen. The study was performed in a double-blind placebo-controlled manner. Results: Incidences of PONY (TSP group: 4.5%, placebo group: 18.2%), requirements of antiemetics (TSP group: 0%, placebo group: 4.5%), and discharge from the hospital (TSP group: 134.8 min, placebo group: 150.0 min) were not different from each other group. There were no severe complications associated with TSP. Total incidence of side effects was higher in the TSP group than the placebo group (TSP group: 59%, placebo group: 14%) (P