The authors report a case of a distal anterior choroidal artery aneurysm in a 75-year-old female who presented with nausea, vomiting, and severe headache. Computed tomographic (CT) scans revealed a hematoma in the right lateral ventricle and a subarachnoid hemorrhage in the right parasellar-Sylvian cistern. Cerebral angiography showed a saccular aneurysm at the right distal anterior choroidal artery. The authors intended to operate at the chronic stage, and carried out conservative management. After 1 month her condition suddenly worsened and she died, although a CT scan showed no remarkable changes. At autopsy, a pulmonary artery thrombosis was considered the cause of death. The aneurysm was identified in the temporal horn of the right lateral ventricle, and was a true aneurysm.