Journal of Autism and Developmental Disorders, Vol. 24, No. 6, 1994 Parent and Teacher Agreement in the Assessment of Pervasive Developmental Disorders p. Szatmari,^ and L. Archer McMasler University and Chedoke-McMaster Hospitals S. Fisman Unitersity of Western Ontario D. L. Streiner McMaster University and Chedoke-McMaster Hospitals Although it is well known that informants often disagree about the degree of psychopathology in children, this issue has not been systematically evaluated in children with autism. The objective of this paper is to estimate the extent of agreement between parents and teachers on the assessment of autistic symp- toms and adaptive behavior skills. We assessed 83 children, 4-6 years of age, with a diagnosis of pervasive developmental disorder (PDD), using the Autism Behavior Checklist (ABC) and the Vineland Adaptive Behavior Scales (VABS). Parents and teachers rated each child on each measure. While there was good agreement between informants on the VABS, teachers tended to rate the PDD children higher that parents. In contrast, there was virtually no agree- ment on the ABC. High levels of stress experienced by parents appeared to be associated with parents reporting more autistic behaviors and less adaptive skills than teachers. As with other child psychiatric disorders, caution must be exercised in combining information from several informants. 'This grant was supported by awards from the Ontario Mental Health Foundation, the Vellum foundation, and Health and Welfare Canada. The authors express their gratitude to the families and clinicians who participated in the project. ^Address all correspondence to P. Szatmari, Department of Psychiatry, Chedoke-McMaster Hospitals, Chedoke Division, Patterson Building, P.O. Box 2000, Station A, Hamilton, Ontario, Canada, L8N .1Z5. 703 0162-3257/94/1200-0703J07.00/0 C 1994 Plenum Publishing Corporalion