Intracranial subdural hematoma is an exceptionally rare but life-threatening complication of spinal anesthesia. We report a case of intracranial subdural hematoma following spinal anesthesia for cesarean section in a 27-year-old woman. She developed a diffuse headache after surgery with a blood pressure of 220/140 mm Hg which was followed by generalized seizure activity. Her blood pressure remained high after medication with diazepam, nifedipine and magnesium sulfate. She remained unconscious with a Glasgow coma scale of 5. The cranial tomography revealed a subdural hematoma with diffuse cerebral edema and cerebral tentorial herniation. When a patient complains of postdural puncture headache and then has seizure activity, one should consider alternative diagnoses, including that of a subdural hematoma, and carry out a careful examination, including magnetic resonance imaging or computerized tomography scan.