Three studies examine the validity of the Preschool Form of the Cognitive Abilities Scale--Second Edition (CAS-2). Significant high concurrent criterion-related validity correlations, corrected for restricted range, are found between the CAS-2 and the Detroit Test of Learning Ability--Primary: Third Edition for 26 three-year-olds (r[subscript c] = 0.86) and the Bayley Scales of Infant Development--Second Edition for 20 two-year-olds (r[subscript c] = 0.63). Significant correlations also are evident for the CAS-2 and the Test of Early Language Development--Third Edition for 26 three-year-olds (r[subscript c] = 0.77) and the Adaptive Behavior Assessment System--Second Edition for 20 two-year-olds ( r[subscript c] = .65). Predictive power is critical when making interpretations regarding future performance. A high, significant correlation (r[subscript c] = 0.72) is observed for the CAS-2 for 37 children at ages 2 and 3 and the Wechsler Intelligence Scale for Children--Third Edition administered 6 years later. Results expand validity evidence for the CAS-2, increasing confidence in interpretations regarding young children's performance.