This study examines agreement between parental reports of children's ADHD outpatient services ascertained with the Child and Adolescents Services Assessment (CASA) and provider records among a sample of elementary school students who participated in an epidemiologically based health services study. Parental reports of any outpatient mental health treatment, services intensity, and medication regimens were compared to records of the specified mental health and primary care providers using intraclass correlations and kappa estimates. Results indicated that parental reports using the CASA produced valid data on whether any outpatient ADHD services had been received in the past 12 months (83% agreement), and on details of the child's medication regimens (kappas above 0.90), but that agreement was poor on how many times the child had been seen (intraclass correlation 0.29), without agreement differences by provider type. These findings support the validity of using parental report for ADHD services in primary care settings and for study of medication regimens.