Background: Wall thickness in the distal part of the left anterior descending coronary artery (LAD) can be measured by using two-dimensional high-resolution transthoracic echocardiography (2DHTTE). The objective of this study was to compare the diagnostic accuracy of measuring carotid intima-media thickness (IMT) and distal LAD wall thickness for prediction of multivessel coronary artery disease (MVD). Methods: We measured wall thickness in the distal LAD using 2DHTTE and carotid IMT using B-mode ultrasound in 100 patients who subsequently underwent coronary angiography (CAG). Patients were classified into three groups based on the results of CAG-no significant stenosis (group N), single-vessel disease (group S), or multivessel disease (group M). Results: Successful measurements of LAD wall thickness were accomplished in 96 patients. Distal LAD wall thickness was significantly greater in group M (0.92 ± 0.20 mm) than in group N (0.72 ± 0.11 mm, P < 0.01) and group S (0. 76 ± 0.19 mm, P < 0.01). Carotid IMT was significantly greater in group M (0.90 ± 0.24 mm) than in group N (0.75 ± 0. 21 mm, P < 0.05) and group S (0.80 ± 0.17 mm, P < 0.05). Distal LAD wall thickness <0.8 mm had a sensitivity of 75% and a specificity of 67% in predicting MVD, whereas carotid IMT >;0.8 mm was 63% sensitive and 67% specific in the prediction of MVD. There was a weak but significant correlation between distal LAD wall thickness and IMT (r = 0.31, P < 0.01). Conclusions: Non-invasive measurement of distal LAD wall thickness by 2DHTTE is feasible, and has equivalent diagnostic accuracy to IMT measurements for predicting MVD. © 2009 Japanese Society of Echocardiography.