Two groups consisting of 10 A.S.A. class I-II neurosurgical patients each were studied to determine whether patients require greater quantities of pancuronium to maintain paralysis after having been given furosemide, 1 mg/kg. After a standardized barbiturate, narcotic and nitrous oxide induction of anesthesia, pancuronium was given intravenously until twitch response was suppressed by 95%. The study group received in addition furosemide, 1 mg/kg, 10 minutes prior to induction of anesthesia. Mean recovery time from 95% to 50% twitch suppression was 21.8 minutes in the control group and 14.7 minutes in the study group. Urinary output was significantly greater (13.5 vs 674 ml) and serum potassium levels lower (4.05 vs 3.85 meq/L) in the study group during recovery of twitch response. Furosemide, 1 mg/kg, facilitates recovery of evoked twitch response after pancuronium.