Cerebral venous thrombosis rarely develops after lumbar puncture and spinal anesthesia with accidental dural puncture, however, occurrence of isolated cortical vein thrombosis after epidural anesthesia is extremely rare. We report three cases who developed postural headache and isolated cortical vein thrombosis after epidural anesthesia. We postulate that intracranial hypotension is the cause of compensatory venous dilatation and resultant thrombosis.