Developmental abnormalities in 16 pediatric patients with AIDS or AIDS-Related Complex (ARC) were previously described. Neurological deterioration was in evidence on follow-up in 9 of the children, 5 died since the original assessments were performed. Ten patients were reevaluated 14 months later by cognitive testing. Two showed greater progress than expected on the basis of earlier test results; 6 showed the expected level of developmental progress; and the remaining 2 showed regression in cognitive functioning. All patients who exhibited regression in their developmental course showed deterioration in their neurological examinations. Developmental progression was noted in some children who on follow-up serial examinations exhibited a clinically deteriorating neurological picture. Pediatric AIDS patients manifest variable neurodevelopmental courses. As a result, rehabilitative intervention services must be tailored to meet individual needs.