The occurrence, location, and severity of muscle pain were determined when vecuronium was used in lieu of succinylcholine during outpatient laparoscopy. Postoperative muscle pain, in 11 body parts, was assessed by a linear analogue scale questionnaire that was completed by each patient on the evening of surgery and for the next three mornings. All patients had general endotracheal anesthesia with nitrous oxide, thiopental, and fentanyl. Succinylcholine 1.5 mg/kg (3-4 min after 3 mg of d-tubocurarine) was given to 14 patients for tracheal intubation and then by infusion for additional muscle relaxation. Another 14 patients received vecuronium 50 micrograms/kg iv as the only muscle relaxant used; all of these patients had residual neuromuscular blockade antagonized with glycopyrrolate 7 micrograms/kg and edrophonium 0.5 mg/kg iv. Both groups were similar in age, weight, length of procedure, time to discharge, and amount of thiopental and fentanyl used (P greater than 0.05). No difference was noted in either group with respect to the severity of pain by body part over time. Mean total body pain scores were generated for each group at all four intervals as an alternate type of analysis. No statistical significance was demonstrated by a Student's t test in any group at any interval sampled. The authors failed to demonstrate that the substitution of vecuronium for succinylcholine lowers the incidence of myalgia when used in outpatient diagnostic laparoscopy. They refrain from concluding that vecuronium contributes to postanesthetic myalgia, but feel justified in stating that the avoidance of succinylcholine did not lower the severity or occurrence of muscle pains after laparoscopy when vecuronium was used in its place.