Cerebral hyperperfusion and reperfusion injuries are not infrequently encountered following in reperfusion of ischemic or hypoperfused brain. Mechanism of injury could be related to tissue plasminogen activator toxicity, oxidative stress, and hyperperfusion due to impaired cerebral autoregulation in already maximally dilated cerebral vasculature and compromised cerebral hemodynamic reserve. Reperfusion injury can present as headaches and seizures in mild forms and as subarachnoid hemorrhage, intracranial hemorrhage, cerebral edema, and encephalopathy in its most severe manifestation. Prevention and identifying those at risk of hyperperfusion syndromes are the best strategy. Active treatment includes basic neurocritical care with reduction of blood pressure to a reperfused brain and timely neuroprotection and cerebral edema control measures are the mainstay of its management approach.