OBJECTIVE To investigate whether continuous epidural droperidol and intravenous (IV) intraoperative droperidol inhibit pruritus and postoperative nausea and vomiting (PONV) during epidural morphine analgesia. METHODS Randomized, double-blinded, controlled study. METHODS Metropolitan cancer center. METHODS 120 ASA physical status I and II patients undergoing thoracic or abdominal surgery with general anesthesia combined with epidural anesthesia. METHODS Patients received an intraoperative epidural injection of 2 mg morphine hydrochloride, followed postoperatively by a continuous epidural infusion of morphine hydrochloride 4 mg/day for 4 days. Patients were randomly allocated to four groups: Group A = control group, Group B = intraoperative single IV injection of droperidol (2.5 mg), Group C = postoperative continuous epidural droperidol infusion (2.5 mg/day), and Group D = intraoperative IV injection of droperidol (2.5 mg) and postoperative continuous epidural droperidol infusion (2.5 mg/day). RESULTS The frequency and severity of pruritus and PONV in each group were evaluated during the postoperative period. Continuous epidural infusion of droperidol significantly reduced the frequency and severity of pruritus and PONV induced by epidural morphine without causing significant side effects. Intraoperative single IV injection of droperidol was effective for PONV (p < 0.05) but not for pruritus. CONCLUSIONS Postoperative epidural droperidol infusion significantly decreased both the frequency and severity of pruritus and PONV during postoperative continuous epidural morphine analgesia. IV intraoperative droperidol significantly reduced the frequency and the severity of PONV but not pruritus.