OBJECTIVE: To investigate the association of visceral fat accumulation and carotid atherosclerosis in non-obese men with normal glucose tolerance. SUBJECTS: Ninety eight middle-aged men with normal glucose tolerances who had a body mass index (BMI) (25 kg/m(2) (mean age: 52.6y, mean BMI: 22.5 kg/m(2)). METHOD: Using ultrasonography, we simultaneously measured the abdominal fat distribution and intima-media thickness (IMT) of the carotid artery wall. RESULTS: Pmax, an index of the absolute amount of visceral fat, was found to be: significantly correlated with IMT and fasting insulin concentration (r=0.37, P<0.005 and r=0.54, P<0.0001). Abdominal wall fat index (AFI), the ratio of maximum thickness of the preperitoneal fat and the minimum thickness of the subcutaneous fat, was not correlated with IMT. CONCLUSION: Visceral fat accumulation may play a role in the progression of atherosclerosis even in non-obese middle-aged men.