Background: This study was designed to know the dose requirement, analgesic efficacy and side effects of butorphanol and nalbuphine when administered with ketorolac by patient controlled analgesia (PCA) after total abdominal hysterectomy. Methods: Forty women who underwent total abdominal hysterectomy received ketorolac (bolus dose 2.4 mg, lockout interval 10 min) with either butorphanol (bolus dose 0.1 mg) or nalbuphine (bolus dose 1 mg) using PCA pump postoperatively. Results: Total amounts of 48 hr consumption were 8.7 mg (butorphanol)and 61.5 mg (nalbuphine). There were no significant differences between two groups in total ketorolac infusion doses, VAS score and side effects. Conclusions: Both butorphanol and nalbuphine were useful for PCA for postoperative pain control. We may suggest that ketorolac 180 mg with butorphanol 9 mg or nalbuphine 70 mg would be useful for 48 hr postoperative pain control.