Seven psychotic children in the diagnostic categories of early infantile autism or childhood schizophrenia and six nonpsychotic children were studied during total nights of spontaneous sleep. The electroencephalogram, eye movements, heart rate, heart rate irregularity and submandibular muscle potential were recorded. The autistic and schizophrenic children showed a similar patterning and percentage of sleep time spent in dreaming to the nonpsychotic subjects and to that reported for normal children of the same age. They also showed the concurrence of several components of the dreaming sleep state, particularly decreased submandibular muscle tone and increased heart rate and heart rate irregularity in conjunction with conjugate rapid eye movements during a stage I EEG. No EEG abnormalities indicative of cerebral dysrhythmia were observed during the seven nights of recording.