In 184 adult patients with severe nonmalignant low back pain from postlaminectomy syndrome, temporary lumbar epidural catheters were infused with either 0.25% bupivacaine 92 mL, fentanyl 600 micrograms, and droperidol 5 mg (Group A), or 0.25% bupivacaine 92 mL, fentanyl 600 micrograms, and NaCl 0.9% 2 mL (Group B). Infusion rates ranged from 0.5 to 2 mL per hour, with an option for turning the infusion off when the patient had no pain and turning it on when the pain returned. Infusions were continued from 2 to 55 days, during which time the patient was at home. In Group A, only two patients had nausea without emesis, while in Group B, nausea occurred in 18 patients (P < 0.04) and four vomited (P < 0.05). The number of patients with headache, pruritus, somnolence, and/or numbness was minimal and without statistically significant group differences. During treatments, pain levels were 2 or less on a 10-cm visual analogue scale. Added to the epidural infusate, droperidol appears to significantly reduce nausea and vomiting in ambulatory patients receiving fentanyl and bupivacaine in extended epidural infusions. The possibility that droperidol potentiates analgesic effects could not be evaluated.