ABSTRACT: Children receiving CNS-directed therapy for cancer are at risk for cognitive problems, with few available empirically supported interventions. Cognitive problems indicate neurodevelopmental disruption that may be modifiable with intervention. This study evaluated short-term efficacy of a computerized cognitive training program and neural correlates of cognitive change.A total of 68 survivors of childhood acute lymphoblastic leukemia (ALL) or brain tumor (BT) with identified cognitive deficits were randomly assigned to computerized cognitive intervention (male, n = 18; female, n = 16; ALL, n = 23; BT, n = 11; mean age ± standard deviation, 12.21 ± 2.47 years) or waitlist (male, n = 18; female, n = 16; ALL, n = 24; BT, n = 10; median age ± standard deviation, 11.82 ± 2.42 years). Intervention participants were asked to complete 25 training sessions at home with weekly, telephone-based coaching. Cognitive assessments and functional magnetic resonance imaging scans (intervention group) were completed pre- and postintervention, with immediate change in spatial span backward as the primary outcome.Survivors completing the intervention (n = 30; 88%) demonstrated greater improvement than controls on measures of working memory (mean ± SEM; eg, Wechsler Intelligence Scale for Children [fourth edition; WISC-IV] spatial span backward, 3.13 ± 0.58 v 0.75 ± 0.43; P = .002; effect size [ES], 0.84), attention (eg, WISC-IV spatial span forward, 3.30 ± 0.71 v 1.25 ± 0.39; P = .01; ES, 0.65), and processing speed (eg, Conners' Continuous Performance Test hit reaction time, -2.10 ± 1.47 v 2.54 ± 1.25; P = .02; ES, .61) and showed greater reductions in reported executive dysfunction (eg, Conners' Parent Rating Scale III, -6.73 ± 1.51 v 0.41 ± 1.53; P = .002; ES, 0.84). Functional magnetic resonance imaging revealed significant pre- to post-training reduction in activation of left lateral prefrontal and bilateral medial frontal areas.Study findings show computerized cognitive training is feasible and efficacious for childhood cancer survivors, with evidence for training-related neuroplasticity.