We report three cases of reversible posterior leukoencephalopathy syndrome (RPLS) in children with cancers. All patients presented with sudden confusional state, visual disturbance, and transient mild hypertension under the treatment of childhood cancers. Magnetic resonance imaging of the brain demonstrated cortical and subcortical lesions predominantly in the occipital region, which showed high intensity signal on fluid-attenuated inversion recovery images. All patients completely recovered from their neuropsychologic deficits only with antihypertensive therapy or discontinuation of the possible offending drugs. Early recognition of RPLS as a complication during cancer therapy in childhood may facilitate precise diagnosis and appropriate treatment.