Objective: Carotid intima-media thickness (CIMT) is reliable marker of subclinical atherosclerosis and cardiovascular events. Until today, there was no study that investigated whether epicardial adipose tissue (EAT), which is a surrogate for lipid depot in a special visceral tissue or circulating lipids, is more important for CIMT and atherosclerotic plaque.Methods: Our study, having cross-sectional and prospective observational design, included 252 patients who were admitted to our outpatient clinic. EAT identified as an echo-free space under the pericardial layer on 2-dimensional echocardiography, was measured perpendicularly in front of the right ventricular free wall at end-systole.Results: EAT significantly correlated with CIMT (r=0.623, p<0.001). CIMT was significantly increased with rising EAT thickness (0.72±0.15 mm, 0.85±0.16 mm, and 0.95±0.12 mm in patients with EAT <5 mm, 5-7, and >7 mm, p<0.001, respectively). Multiple linear regression analysis revealed that age (Beta: 0.406, p<0.001), male gender (Beta: 0.244, p<0.001), and EAT (Beta: 0.450, p<0.001) as independent correlates of CIMT. Otherwise, in logistic regression analysis, only EAT (OR, 1.386; 95% CI, 1.203-1.597, p<0.001) and LDL cholesterol (OR, 1.013; 95% CI, 1.002-1.013, p=0.02) were independent predictors for presence of carotid plaque.Conclusion: Our study showed that EAT has a relationship with both CIMT and the presence of carotid plaque, but LDL is independently related to the plaque. This finding suggests that EAT thickness may be a risk factor and biomarker, playing an important role beginning from early stages of atherosclerosis, unlike LDL cholesterol, which appear to have a role in later stages of atherosclerosis.