This research evaluated parent reports of sleep behaviors of four groups of children: those with Autism or Pervasive Developmental Disorders, those with General Mental Retardation alone, those attending Special Education classes (with no MR diagnosis), and a control group of similar aged children without a developmental diagnosis. Diagnostic classification and demographic information were determined through parent report, report of classroom registration, and the Gilliam Autism Rating Scale (Gilliam, 1995). To evaluate sleeping behavior the study used a 28-item, five-factor scale (Behavioral Evaluation of Disorders of Sleep/BEDS; Schreck, 1997/1998) constructed from the diagnostic criteria for childhood sleep disorders found in the International Classification of Sleep Disorders: Diagnostic and Coding Manual (ICSD, American Sleep Disorders Association, 1990). Findings suggest that reports of parents with children with autistic characteristics exhibit expected quantities of sleep, but parent perception of their sleep difficulties and sleep quality is different for children with autism than for children in all other study groups.