The present study examined the relationships between the standardized applied behavior analysis (ABA) direct assessment, the PEAK Comprehensive Assessment (PCA), and established assessments commonly used in educational and clinical settings, including the Childhood Autism Rating Scale - Third Edition (CARS-3), the PDD Behavior Inventory (PDDBI), the Vineland Adaptive Behavior Scale - Second Edition (VABS-2), and intelligence, including the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV) and the Wechsler Intelligence Scale for Children (WISC-V). Utilizing a sample of 73 children with autism ranging from 3 to 21 years old, the present study found the PCA to be significantly correlated with the established measures. The result suggests evidence of convergent validity of the PCA, and internal consistency among its subtests. Implications of this behavior-analytic standardized assessment were discussed.