Coronary artery ectasia (CAE) is usually considered a variant of coronary artery atherosclerosis; however, a definite link has not yet been confirmed. As not all patients with CAE are symptomatic, the real incidence is unknown. The aim of this study was to evaluate the prevalence of CAE and its clinical and angiographic characteristics as well as its relation to coronary artery calcification and any associated vascular abnormality by using multidetector computed tomography (MDCT). We prospectively enrolled 2,600 patients (mean age 55 ± 10 years) who were scheduled for computed tomography coronary angiography (CTCA). CTCA was performed using 64-MDCT with dedicated software for calcium measurement. CAE was defined as an arterial segment with a diameter of >1.5 times the diameter of the adjacent normal segment. The presence of ≥70 % diameter stenosis of any major epicardial vessel was considered an obstructive lesion. CAE was encountered in 192 (7.4 %) patients and showed gender predominance in men (88 %). Patients with CAE were more hypertensive but less diabetic. Left anterior descending artery was the most commonly affected vessel. Only 16 % of CAE patients had no atherosclerotic lesion. Coronary artery calcium score (CACS) and prevalence of ascending aorta aneurysm were shown to be significantly higher in CAE patients compared to patients having no ectasia. A significant negative correlation was noted between CACS and Markis classification. CTCA is a feasible technique to identify and evaluate morphology of CAE. The link between CACS and CAE may favor the consideration that ectasia is an advanced form of atherosclerosis.