A 71-year-old woman was admitted to our critical care center because of disturbance of consciousness of sudden onset. Computed tomography showed a subarachnoid hemorrhage. Angiography revealed a ruptured cerebral aneurysm at the tip of the basilar artery. We performed endovascular surgery to prevent rebleeding. The aneurysm was embolized with Guglielmi detachable coils, and complete occlusion was achieved. The patient regained consciousness. Angiography on the 12th day revealed no recurrence of the aneurysm and no vasospasm due to subarachnoid hemorrhage. The patient was disoriented but retained normal motor, sensory, and verbal functions. She was discharged from our critical care center and was transferred to another ward for rehabilitation. The efficacy of endovascular coiling for ruptured cerebral aneurysms was proven by the International Subarachnoid Aneurysms Trial. Thereafter, aneurysmal subarachnoid hemorrhage has often been managed with endovascular treatment rather than neurosurgical clipping. Advanced skills are needed to perform both endovascular treatment and neurosurgical clipping.