The effect of epidural nalbuphine on pruritus, nausea, vomiting, voiding difficulties and/or analgesia induced by epidural morphine was determined in sixty Cesarian delivery patients. They were physical status 1 or 2 by ASA classification and randomly divided into three groups. They were administered morphine 3 mg only(group A), nalbuphine 5 mg with morphine 3 mg(group B), or nalbuphine 10 mg with morphine 3 mg(group C) at the time of peritoneal closure. During postoperative 24 hours their analgesic effects were evaluated by visual analogue scale(0~10). Respiratory rates, Trieger dot test and severity of side effects(0~2) were also evaluated. The results were as follows; 1) Analgesic duration of the first epidural administration was significantly long in group A than other groups, but there was no difference between that of group B and group C. 2) Pruritus was more severe in group A than other groups but the severity was decreased by increasing nalbuphine dosage. 3) Nausea and or vomiting was mild in group C and the incidence of nausea and/or vomiting combined with pruritus was decreased by increasing nalbuphine dosage. 4) Voiding difficulties was more severe in group A than other groups but the severity was not decreased by increasing nalbuphine dosage. 5) None of the patients had objective sedation or low respiration rate(< 10 times/minute). We concluded that epidural administration of nalbuphine 10 mg with morphine 3mg for post-Cesarean section pain management is one of good methods to reduce side effects induced by epidural morphine.