Objectives: Common carotid intima-media thickness (CIMT) is weakly correlated with the extent of coronary atherosclerosis. We sought to evaluate the correlation between the extent of coronary atherosclerosis and the each wall thickness of common carotid artery. Methods: Study subjects consisted of 984 consecutive patients (mean 59.9짹11.4 years old, 533 males) who were underwent coronary angiography and carotid scanning for the measurement of the each carotid arterial wall thickness using high-resolution ultrasound and the dedicated software. Patients were divided into 0 to 3 groups according to the number of significantly stenosed (>50%) major coronary arteries: group 0 (n=363, mean 58.3 yrs old, 165 males), group 1 (n=298, mean 59.5 yrs old, 170 males), group 2 (n=196, 62.4 yrs old, 119 males), and group 3 (n=127, mean 61.1 yrs old, 79 males). Results: CIMT, intimal thickness (CIT), and medial thickness (CMT) were 0.7380.11mm, 0.3380.03mm, and 0.4530.09mm in all study subjects, respectively. The extent of coronary atherosclerosis was correlated with CIT only (r=0.122, p=0.012), not the CIMT (r=0.057, p=0.153) nor CMT (r=0.037, p=0.454). See the graph for the each arterial wall thickness (mm). Conclusions: Carotid intimal thickness, not the carotid intima-media thickness is correlated with the extent of coronary atherosclerosis.