We evaluated the neuromuscular reversal with edrophonium using peripheral nerve stimulator and recorder in a patient with malathion intoxication. Edrophonium 10 mg i.v. caused an increase in single twitch tension by 76% of the control during the recovery phase from an acute cholinergic crisis 16 days after ingestion of malathion solution. The present study indicated that edrophonium test seems to be a reliable monitoring in evaluating neuromuscular reversal in the patient with acute malathion insecticide poisoning.