This study examines the early neurodevelopmental function of infants and preschool children who have chronic kidney disease (CKD). Fifteen patients with CKD are compared to a healthy control group using the "Mullen Scales of Early Learning" (MSEL) and the "Vineland Adaptive Behavior Scale" (VABS). Multivariate analysis reveals significant differences between the CKD and control groups on both MSEL (p less than 0.01) and VABS (p less than 0.001) composite scales, with the group with CKD obtaining lower scores on both composites. A higher proportion of children with CKD meet federal eligibility criteria for early cognitive delay, but similar proportions are found across adaptive behaviors. Disease severity is positively correlated to cognitive and adaptive functioning such that lower scores are associated with less renal function (MSEL r = 0.62, p less than 0.001; VABS r = 0.70, p less than 0.001). Suggestions are made in regard to special education assessment and service provision. (Contains 2 tables.)