We investigated the relative impacts of visceral adiposity and insulin resistance on the metabolic risk profile in middle-aged Japanese men. A cross-sectional study was conducted in 636 nondiabetic Japanese men with a mean age of 51.6 years. Visceral adipose tissue (AT) was assessed using computed tomography, and insulin resistance was determined by the homeostasis model assessment of insulin resistance (HOMA-IR). Metabolic risk factors were diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III metabolic syndrome criteria: (1) hypertriglyceridemia, (2) low high-density lipoprotein cholesterol, (3) hypertension, (4) impaired fasting glucose, and (5) impaired glucose tolerance. Visceral AT and HOMA-IR were significantly and positively correlated with each other (r = 0.41, P < .001). Using the 75th percentile value as a cut point, those with isolated large visceral AT showed significantly greater odds ratios for each of the 5 risk factors measured except impaired fasting glucose, whereas those with isolated high HOMA-IR showed significantly greater odds ratios for each of the 5 risk factors except hypertriglyceridemia and impaired glucose tolerance, compared with the control group. The combined group (increased visceral AT and HOMA-IR) had the highest odds ratios for all studied risk factors. On logistic regression analysis using visceral AT and HOMA-IR as continuous independent variables, they were each independently associated with most of the metabolic risk factors and their clustering. In conclusion, neither visceral AT nor HOMA-IR stands out as the sole driving force of the risk profile; each makes a significant contribution to metabolic abnormalities in Japanese men.