The authors investigated the relation between coronary atherosclerosis, angiographically detected, and intimal-medial (I-M) thickening of the common carotid artery (CCA), as measured by high-resolution B-mode ultrasound system. They studied 31 patients with coronary artery disease (CAD) and 23 healthy control subjects. I-M thickening of CCAs and atheromatous plaques at the carotid bifurcation were evaluated. A score system was defined (range 0-20) based on the absence or presence of atherosclerotic lesions at common and internal carotid arteries. A coronary angiography score was defined based on the presence of of atherosclerotic lesions at nine coronary arterial segments (range 0-36). The thickness of CCAs (M +/- SD) in CAD patients was significantly higher (1.45 +/- 0.95 mm) than in controls (0.87 +/- 0.10 mm, P < 0.005), and an I-M thickening of 1.1 mm or more was specific and positively predictive of CAD. A significant positive correlation between coronary and carotid score was observed (P < 0.028, r = 0.373). The study suggests that I-M thickening could be helpful for the identification of patients at risk for CAD.