Posterior reversible encephalopathy syndrome (PRES) is a clinico-neuroradiologic disease entity represented by characteristic magnetic resonance image (MRI) findings of subcortical/cortical hyperintensity in T2-weighted sequences, more often observed in parieto-occipital lobes, accompanied by clinical neurologic alterations. PRES is a rare central nervous system complication in childhood hematologic-oncologic patients and shows very different neurologic symptoms between patients, from numbness on extremities to generalized seizure. The etiology of PRES was not well known until these days. In this study, 8 patients with PRES were reviewed, retrospectively. There were 4 patients with acute lymphocytic leukemia, 1 with aplastic anemia, and 3 with solid tumors (1 patient each for neuroblastoma, Ewing sarcoma, and osteosarcoma). Allogeneic stem cell transplantation was performed in 2 patients. Immunosuppressive agents such as tacrolimus and cyclosporine A were used in 3 patients. One neuroblastoma patient was in immediate postoperative status. All patients experienced seizure attacks of different types and showed typical MRI findings. Follow-up MRIs revealed significant improvements. From this review, we might consider chemotherapy and surgery as additive causes for PRES other than immunosuppressive agents. Therefore, careful examination of the patients receiving chemotherapy and surgery was needed to find out this uncommon but good prognostic complication.