The acute muscarinic and nicotinic side-effects of organophosphate poisoning are well known. Less commonly encountered are neurological symptoms such as chorea and psychiatric disturbances such as psychoses and depression. Two patients with organophosphate poisoning are described, both exhibiting marked choreiform dyskinesias and one experiencing severe depression and emotional lability. Both responded well to the appropriate treatment. Because of the widespread use of organophosphate insecticides in agriculture, the neurological and psychiatric effects of chronic low-dose exposure to organophosphates in farmers and their employees deserves attention.