Background Large hemispheric strokes have a high risk of fatal cerebral edema and brain herniation also known as  “Malignant infarction of the middle cerebral artery” (MIMCA),this  is a severe complication of arterial ischemic stroke seen  in the adult population. The description of malignant MCA stroke syndrome in the pediatric population is very scarce(1,2).Objectives Describe the most common clinical, radiological and electrographic features associated with malignant MCA syndrome at the Hospital for Sick Children Methods Patients with a diagnosis of arterial ischemic stroke. A retrospective review of the clinical and radiological  findings was performed ,  from a prospectively collected  patients  throughout the stroke database at the Hospital for Sick Children.Results We identified  117 children carrying the diagnosis of stroke at the Stroke Program at the Hospital for Sick Children in Toronto, ON Canada from January 2005 to September 2012. .  Among these,  69 (58%) had MCA territory involvement. We identified 12 (17%) patients that developed malignant MCA syndrome.  The mean age was 6.7 years (range from 0.08 to 15). Conclusion Malignant cerebral edema, is a severe complication of infarcts involving the middle cerebral artery territory. These patients have a more severe deficit on presentation and also prolonged seizures . Large territorial infarcts, and proximal artery occlusion is also seen in these patients. The early recognition of these findings, could be helpful for clinicians in order to identify patients at risk.