Acetylcholinesterase is responsible for the hydrolysis of acetyl choline into acetic acid and choline. Acetylcholine is an important chemical transmitter substance in the nervous system of helminth parasites. Acetylcholinesterase activity have been biochemically estimated in Neyraia multicornata. Significant amount of the enzyme was present in the helminth parasite. The possible functional role of cholinesterase in helminth parasites was discussed.