A detailed psychometric-psychologic-neurologic evaluation, carried ourt18 months to 14 years after an acute episode of poisoning, revealed no over-all difference between 41 children who had had acute central nervous system (CNS) intoxications and 41 paired control patients who had ingested a toxic agent but had had no acute CNS symptoms. Of the 8 children in the, study group who had had convulsions of variable duration, 6 have Binet scores below 90 (p<0.001) and only one of the 8 has no learning or behavioral difficulties. Chlroinated hydrocarbon insecticides were the principal cause of toxic convulsions, and all 4 children in this group had subsequent major difficulties. Although the effects of anoxia from protracted seizures and specific CNS toxicity are not differentiated, the findings suggest the value of a prospective, collaborative study by poison control centers of the relationship of toxic convulsions to subsequent learning disorders in young children.