Traumatic acute subdural hematoma (ASDH) is generally addressed by craniotomy under general anesthesia. We report a patient whose traumatic ASDH was treated under local anesthesia by one-burr-hole endoscopic surgery. This 87-year-old woman had undergone coil embolization for a ruptured right middle-cerebral artery aneurysm and placement of a ventriculoperitoneal shunt for normal pressure hydrocephalus 5 years earlier. Upon admission, she manifested consciousness disturbance after suffering head trauma and right hemiplegia. Her Glasgow Coma Scale score was 8 (E2V2M4). Computed tomography (CT) demonstrated a thick, left-frontotemporal ASDH. Due to her advanced age and poor condition, we performed endoscopic surgery rather than craniotomy to evacuate the ASDH. Under local anesthesia, we made a burr hole in her left forehead and increased its size to 15 mm in diameter. After introducing a transparent sheath into the hematoma cavity with a rigid endoscope, the clot was evacuated with a suction tube. The arterial bleeding point was electrically coagulated. A postoperative CT scan confirmed the reduction of the hematoma. There was neither brain compression nor brain swelling. Her consciousness disturbance and right hemiplegia improved immediately. Endoscopic surgery may represent a viable method to address traumatic intracranial hematomas in some patients.