OBJECTIVE: The purpose of this non-randomized prospective study was to evaluate the safety and efficacy of continuous intravenous nalbuphine-ketorolac-droperidol(CIA) versus continuous infusion of epidural morphine-bupivacaine(CEA) for pain control after lumbar spinal surgery. METHODS: Twenty-one patients who underwent spine surgery including laminectomy, fusion with fixation were assigned to receive an intravenous bolus of nalbuphine 5mg and ketorolac 15mg, followed by a continuous infusion of nalbuphine 25mg, ketorolac 105mg, and droperidol 5mg mixed with normal saline 98cc(2cc/hr). Twenty patients received a bolus infusion of morphine 2mg and 0.125% bupivacaine 8cc followed by a continuous intravenous infusion of 100cc 0.125% bupivacaine and morphine sulfate 8.0mg(2cc/hr). Pain score was measured on a visual analogue scale(VAS). It's safety and efficacies were compared with the results of continuous infusion of epidural morphine-bupivacaine, which was reported previously by same authors. A continuous infuser was used to give epidural morphine-bupivacaine and intravenous nalbuphine-ketorolac-droperidol. RESULTS: In general, mild pain, pain less than 3 VAS scores, was observed postoperatively from 30minutes to 72hours in CEA group, and from 6 hours to 72 hours in CIA group. The early postoperative pain was controlled easily in 6 hours in CEA group, compared to CIA group(p<0.05). However, there was no statistical significance in 72 hours on pain scores between CEA and CIA groups after 6-12hours of pain managements. Pruritus, nausea and vomiting, and urinary retention were more frequent in CEA group. CONCLUSION: CIA and CEA are considered effective methods in postoperative pain managements. However, adequate doses in early intravenous infusion and continuous intravenous analgesia with nalbuphine-ketorolac-droperidol will be needed for better control in early postoperative pain with less side effects.