A substantial body of research in adults has established that certain sleep polysomnographic abnormalities are commonly found in depressed patients, including sleep continuity disturbances, reduced slow-wave sleep, shortened rapid eye movement (REM) latency, and increased REM density. To date, these abnormalities have not been documented in depressed children compared with age-matched controls. Three consecutive nights of polysomnographic recordings were obtained in 25 hospitalized depressed children and 20 age-matched healthy controls. The depressed patients had reduced REM latencies. The shortest single-night REM latency of each individual was the most sensitive discriminating value between depressed subjects and controls. The influence of different scoring criteria in distinguishing depressed children from healthy children is discussed. In addition, depressed children had an increased sleep latency and increased REM time but did not have stage 4 differences.