The intermediate syndrome of organophosphate poisoning arises in the time interval between the acute cholinergic crisis of fasciculations and muscle weakness and the delayed neuropathy attributed to inhibition of the neuropathy target esterase. The conclusions derived from salient experimental and clinical studies are that intermediate syndrome relates to the severity of poisoning not the specific organophosphate and to prolonged inhibition of acetylcholinesterase activity of the erythrocytes, brain and muscle endplate with pre and post synaptic impairment of neuromuscular transmission. It is not related to delayed neuropathy.