The ability of edrophonium to reverse the nondepolarizing neuromuscular blockade produced by pancuronium was studied in 40 adult patients during light nitrous oxide–enflurane anesthesia. Antagonism of paralysis was attempted when the train-of-four fade ratio had spontaneously recovered to various extents. Edrophonium was administered in incremental doses intravenously either until the fade ratio increased to 0.70 or more or until the total dose of drug amounted to 0.5 mg/kg. All patients who had spontaneous recovery of train-of-four fade ratios to at least 0.10 had adequate reversal with edrophonium. When the train-of-four count was three or fewer visible twitches, the response to edrophonium was unpredictable. No evidence of recurarization was seen.