Cerebral infarction may be associated with underlying aneurysms. Such episodes
of ischemia may be caused by thromboembolism, emboli originating from a thrombosed aneurysm, or may be secondary to an occlusion of the parent vessel with a thrombus.1,2 Mechanical obstruction of the cerebral artery by a neighbored lesion might be one possible cause of cerebral infarction. This should be considered if the symptoms and signs of cerebral infarction follow such a disorder as subarachnoid hemorrhage or mass are shown by a positive imaging study. Here we report a case of cerebral infarction due to anterior choroidal artery occlusion caused by posterior communicating artery aneurysm.