Malignant infarction implies a large middle cerebral artery (MCA) stroke that leads to rapid clinical deterioration and edema formation, and can be associated with hemorrhagic transformation, herniation, and poor functional outcomes, including death. Malignant edema is brain edema formation that occurs in the setting of large territory infarction. This review discusses the most recent efforts in diagnosis, prevention, and management of malignant edema in acute ischemic strokes.