Eptastigmine or heptylphysostigmine is a competitive inhibitor of acetylcholinesterase. Eptastigmine leads to an improvement in the cerebral blood flow in the ischemic brain, excitatory and inhibitory effects on the gastrointestinal tract and to a protection from acute soman and diisopropylfluorophosphate intoxication. Eptastigmine, by either acute or chronic administration, has been found to have memory enhancing effects in different species of normal, aged and lesioned animals. It also restored to normal the age-related increase of EEG power without affecting spontaneous motor activity. Eptastigmine produces significant cognitive, clinical, and functional benefits in patients with probable Alzheimer's Disease. Although the cholinergic tolerability of eptastigmine was found to be favorable, its potential adverse hematologic effects limit its clinical utility.