We investigated the relationship between cigarette smoking and silent brain infarction in 365 neurologically normal male Japanese subjects (smokers: 119, nonsmokers: 246). Silent brain infarction was identified in 32 (26.9%) of 119 smokers and in 54 (22.8%) of 246 nonsmokers. Mild or moderate periventricular hyperintensity was presented in 27 smokers (22.7%) and 54 nonsmokers (22.8%). There was no significant difference in the regional cerebral blood flow or the average systolic, diastolic, and mean arterial blood pressures between groups. The HDL-cholesterol level was significantly lower in smokers than in nonsmokers (p < 0.01). Cigarette smoking was not related to the incidence of silent brain infarction or leuko-araiosis in healthy adults in Japan.