A 66 year-old diabetes mellitus man suffered from right hemiplegia on the morning Dec. 2, 1991. After admission, severe dyspnea developed on Dec. 5 and HHNK (hyperglycemic hyperosmolar non-ketoacid coma) was diagnosed. At the same time, right femoral artery occlusion occurred. Heparin was given. He was died on Dec. 7, 1991. After autopsy, we proved a classic case of diabetes mellitus with prominent atherosclerosis resulting in brain infarct and femoral artery occlusion. The casue of death was due to bronchopneumonia.