The analgesic efficacy and side-effects of combined continuous epidural infusion of bupivacaine and morphine, in comparison with intramuscular (IM) administration of narcotics, for postoperative pain relief after cesarean section and hysterectomy were evaluated. We divided 60 patients into 4 groups randomly. IM (meperidine) group after cesarean section (Group 1, n = 20); Continuous epidural group after cesarean section (Group 2, n=20); IM (meperidine) group after hysterectomy (Group 3, n=10); Continuous epidural group after hysterectomy (Group 4, n=10). Following each operation, the epidural groups had an epidural catheter placed ($L_{2{sim}3}$ or $L_{3{sim}4}$), and a bolus of 1.5mg of morphine was injected, and followed by continuous infusion of 0.3% bupivacaine 2ml/hour and morphine 2.5mg/day for 48 hours. The IM groups had received meperidine 50mg IM injection every 4 hours as needed. We evaluated analgesic efficacy with VAS (visual analogue scale) at 1, 2, 24, 48, and 72 hours after operation. The side-effects (nausea &, vomiting, respiratory depression, pruritus and urinary retention) were evaluated with 4 points scale at day 1, 2, and 3 after operation. The results were as follows 1) The continuous epidural (bupivacaine+morphine) groups were superior to the IM (meperidine) groups with respect to postoperative analgesia at 1, 2, and 24 hours after cesarean section, and at 1, 2, 24, and 48 hours after hysterectomy. 2) Vomiting were more frequent in the epidural groups 2 days after cesarean section. 3) Pruritus was more frequent in the epidural groups 1 and 2 days after cesarean section.