Background: Coronary artery ectasia (CAE) is one of the controversial clinical entities of cardiology because of an obscure etiology and usually considered a variant of coronary atherosclerosis. Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) have been shown to be good surrogate markers of atherosclerosis. The aim of study was to assess the carotid IMT and FMD of brachial artery in patients with isolated CAE. Methods: We included 27 patients (mean age; 57짹8 years, male%; 26) who had isolated CAE (Markis type I/II %; 51%, diameter of ectasia; 5.6짹0.7mm), 30 patients (mean age; 60짹11 years, male%;27) who had stable angina with CAD in angiography, 25 cardiac SD-X (mean age; 55짹9years, male%; 28). FMD was measured by use of high-resolution ultrasound as the percent change of brachial artery diameter after 3 min occlusion. IMT was taken as the distance between the leading edge of the first echogenic line of the far wall of carotid artery and leading edge of the second echogenic line. Results: The demographic data were similar among three groups, except more frequent diabetes in CAD. Results are shown in the table. Conclusions: The isolated CAE have less impaired endothelium-dependant vasodilatation than CAD and SD-X and less atherosclerosis of carotid artery than CAD. It suggests that the pathogenesis of isolated CAE in the different to the classical CAD and SD-X.