PURPOSE: To determine the location and distribution, as seen on cerebral angiograms, of severe atherosclerotic stenosis of atherosclerotic or occlusion among Koreans and to thus be aware of the differences in distribution of these conditions between Koreans and other ethnic groups included in previously reported data. MATERIALS AND METHODS: We retrospectively reviewed the cerebral angiographic findings of 268 patients in whom angiography had revealed at least one instance of severe stenosis (ss) (<70 %) and who had more than one risk factor for atherosclerosis. The review was focused on the location of the stenosis and multiplicity of the lesion. Statistical analysis employed the chi-square test, and the data obtained was compared with that reported for other ethnic groups. RESULTS: A total of 389 SS sites were detected in 268 patients. Isolated severe stenosis (IS) was found in 56 patients (21%), and multiple stenoses (MS) in 212 patients (79%). Lesions were located in the intracranial portion in 52 % of cases, and in the extracranial portion in 48%(p<.05). They were found in the anterior circulation in 59% and in the posterior circulation in 41 %(p<.05). Thirty-seven of 56 IS (66 %) were located in the intracranial portion and 19 (34 %) in the extracranial portion (p<.05). One hundred and sixty-seven(50 %) of 333 lesions involving multiple stenoses were seen in the extracranial portion, while 166 (50%) were located in the intracranial vessels. The higher prevalence of intracranial stenosis in the IS group than in the MS group was statistically significant (p<.05). CONCLUSION: On the basis of previously reported data, Korean patients with severe atherosclerotic stenosis tend to have more frequent multiple and intracranial stenoses than do Caucasians. Intracranial stenosis was more frequent in the isolated stenosis group than in the multiple stenosis group.