Cerebral hyperperfusion syndrome is a major cause of morbidity and mortality following carotid artery stenting (CAS). We present a case of acute subdural hematoma (SDH) 2 hours after CAS. In this case, arterial origin of bleeding was verified during operation. To our knowledge, there is no prior case report of SDH without intraparenchymal nor subarachnoid hemorrhage subsequent to CAS. We postulate that SDH was caused by sudden rise in intracranial pressure due to the hyperperfusion which disrupted a corticodural bridging artery.