Purpose: to evaluate current role of magnetic resonance imaging in diagnosis, characterization and follow up of pres in pediatric cancer patients. Methods: we identified 50 cases of children diagnosed with extra cranial cancer with cns manifestations suspecting pres. patients presented to radiology department in (57357-cche) 2013-2015. Results: there was slightly male predominance (56%). 62% of patients were less than 10 years of age with median age 8.5 years. pres developed in 74% of patients within less than 6 months from the start of treatment while 26% developed it more than 6 months. primary diagnoses were leukemia (n = 36), lymphoma (n = 9), neuroblastoma (n=3) and post bmt (n = 2). convulsions were the most frequent presenting symptom (78%) of the patients, ams (34%), headache (26%) and visual impairment occurred in 6% of studied patients. mri study revealed that atypical pres (62 %) was more common than typical type with posteriorly dominant disease noted in 45 cases, 7 cases showed restricted diffusion and 4 cases showed post contrast enhancement. 41 patients underwent follow up mri study, where, 23 of them showed complete radiological resolution, 10 patients showed regressive course while 7 cases showed progressive course. Conclusions: pres is more common in children with hematological malignancies with reversible radiologic outcomes in most of the cases yet small number of patients will develop persistent brain damage. mri is the gold standard for diagnosing pres. atypical pres, areas of true restricted diffusion or post contrast enhancement showed higher incidence of poor prognosis.