Iatrogenic cognitive impairments have been reported for survivors of childhood leukemia after prophylactic central nervous system therapy with craniospinal radiation. To determine whether chemotherapy alone might be a source of central nervous system damage, we assessed in a cross-sectional design the cognitive and academic functioning of 48 children with acute lymphocytic leukemia who were at various stages in their treatment or who had completed treatment. The off-therapy patients who had completed a 3-year course of chemotherapy were more impaired in tasks of higher-order cognitive functioning than were those children whose leukemia had been newly diagnosed and those children whose diagnoses had been 1 year earlier. Off-therapy patients also had concomitant diagnosable learning disabilities in mathematics. We recommend appropriate liaison and special education placements, as well as continued evaluation of cognitive and leaning functioning of children treated for moderate-risk acute lymphocytic leukemia who receive chemotherapy alone.