Optic chiasmal syndrome due to arteriosclerotic vascular changes is rate. To our knowledge, there has been no report of arteriosclerotic chiasmal syndrome in Korea. In our two cases, other causes of chiasmal syndrome were not detected by MRI, four-vessel cerebral angiography, CSF study, and special laboratory examinations including ANA test, RA factor, and LE cell. With conservative treatment, the visual fields of the two patients are showing progressive improvement. We report here two cases of suspected arteriosclerotic optic chiasmal syndrome.