Sixty-three autistic children have been reevaluated at a mean age of 15 years after a mean follow-up period of 9 years. Almost one third have achieved at least a moderate social adjustment. The prognosis has been shown to vary significantly with the presence of useful speech at the age of 5, taken as an index of the severity of autistic isolation. Half of those who possessed meaningful language by the age of 5 improved, whereas only 1 of 31 without the ability to communicate verbally by that age has shown significant improvement. The clinical course of these children justifies the segregation of early infantile autism as a clinical entity, probably to be included within the group of schizophrenias. The psychopathology of autism has been reviewed and the suggestion offered that the fundamental feature is a disturbance in social perception.