There is increasing evidence that arterial intima-media thickness (IMT) might represent an early atherosclerotic lesion. The clinical importance of its measurement is, however, still debated. The aim of the present study was to analyze the effect of coronary heart disease (CHD) risk factors on carotid IMT and to verify whether intima-media thickening is associated with overt atherosclerosis of carotid arteries. Two hundred and seventy-six subjects referred to the Angiology Unit for echo-Doppler examination of carotid arteries during the period January-June 1993 were enrolled. Echo-Doppler was performed with a Multigon Angioview 600. IMT was measured in the common carotid artery, 1 cm proximal to the bulb. CHD risk factors were evaluated by routine methods. In males IMT increased significantly with increasing number of CHD risk factors. In females only the presence of three CHD risk factors was associated with a significant IMT increase. In both sexes IMT was higher in subjects with evidence of atherosclerotic lesions in the carotid arteries. In multiple regression analysis IMT was strongly and significantly associated with the presence of plaques and/or stenosis in the carotid arteries. The present findings suggest that IMT measurement can be useful in clinical practice, giving a comprehensive picture of the damage caused by several CHD risk factors over time on arterial wall.