In order to determine the effect of two standard general anesthetic techniques on the postoperative analgesic requirement, 53 adults undergoing elective intra-abdominal surgery were randomly assigned to one of two anesthetic treatment groups according to an open parallel protocol design. One of the groups received an opioid-based anesthetic; the other group was administered an inhaled anesthetic. The postoperative analgesic requirement was quantified using a Baxter PCA device. The group receiving the opioid-based anesthetic required significantly less morphine in the recovery room (5.7 +/- 5.5 mg; mean +/- SD) compared with those receiving the conventional inhaled anesthetic (16.6 +/- 7.1 mg). During the first 8 hours after discharge from the recovery room there was a trend toward higher PCA morphine usage in the inhaled anesthetic group (25.6 +/- 15 mg vs. 18.6 +/- 13 mg); however, this difference was not statistically significant (p = 0.08). From 8 to 40 hours after surgery, the morphine usage was nonsignificantly higher in the opioid group (64 +/- 30 mg vs. 56 +/- 38 mg, p = 0.43). In conclusion, the general anesthetic technique used during an elective operation appeared to have little if any effect on the postoperative analgesic requirement after discharge from the recovery room.