We described an autopsy case of a ruptured aneurysmal subarachnoid hemorrhage treated with endovascular embolization by interlocking detachable coils. An 85-year-old male presented with sudden onset of severe subarachnoid hemorrhage. Cerebral angiogram revealed a right internal carotid-posterior communicating artery aneurysm. Post-operative angiogram revealed complete obliteration of the aneurysm, except for its orifice. Following the embolization of the aneurysm, tissue plasminogen activator was intrathecally perfused for anti-vasospasm treatment. Follow-up angiogram showed stable obliteration of the aneurysm, and no particular findings of cerebral vasospasm. The patient had been recovering without any neurological deficits, but died from pneumonia on the 25th day after the embolization. Autopsy findings revealed the disappearance of the subarachnoid hemorrhage, and no visible finding of cerebral infarction or edema. The inner lumen of the aneurysm was occupied by a mixture of the coils and the clots. The surface of the embolized coils was directly observed through the orifice of the aneurysm without any membranous substance from the inner lumen of the internal carotid artery. This pathological finding is different from the previously reported animal models in which the surface of the embolized coils was covered with endothelial membrane 2 weeks after embolization. Further examinations are required to clarify the pathogenesis of the endothelial regrowth.