Background The relationship between abdominal visceral fat accumulation and lacunar infarcts has not been previously investigated in Japanese men. Methods and Results The subjects were 637 middle-aged (40-64 years) and 222 elderly (65-79 years) men who participated in a health checkup program from 1999 to 2003. The association between lacunar infarcts identified by magnetic resonance imaging and cardiovascular risk factors, including abdominal visceral fat accumulation evaluated by computed tomography, was examined. The prevalence of lacunar infarcts was 4.9%. Hypertension was associated with lacunar infarcts among both the middle-aged men [age-adjusted odds ratio (OR)=2.9 (95% confidence interval (CI): 1.1-7.8)] and the elderly men [OR=5.1 (95%CI: 1.4-19.0)]. Abdominal visceral fat accumulation was slightly associated with lacunar infarcts among middle-aged men, but not among elderly men: OR in the highest (≥117 cm²) vs lowest (≤83 cm²) tertiles of fat area was 2.6 (95%CI: 0.9-7.6) for middle-aged men. Extreme accumulation of visceral fat (≥143 cm²) was still slightly associated with lacunar infarcts after adjustment for age, hypertension, drinking and smoking among middle-aged men [OR=2.7 (95%CI: 0.8-9.1)]. Conclusions This cross-sectional study suggests that abdominal visceral fat accumulation is a possible risk factor of lacunar infarcts, in addition to hypertension, in middle-aged Japanese men. (Circ J 2004; 68: 982 - 987)