Epicardial adipose tissue (EAT), localized beneath the visceral pericardium, is a metabolically active endocrine and paracrine organ with possible interactions within the heart. Recent studies identified possible roles of uric acid (UA)-induced oxidative stress and increased inflammatory status in the pathogenesis of ascending aortic dilatation. The aim of this study was to investigate whether EAT is an independent factor for ascending aortic dilatation. The patients were evaluated by a complete transthoracic echocardiographic examination including measurements of EAT and aortic dimensions. Serum levels of UA and C-reactive protein and EAT thicknesses were compared in 38 patients with dilated ascending aorta (DAA) (the diameter ≥ 37 mm) vs. 107 subjects with normal aortic diameter (AD) of < 37 mm. EAT thickness was significantly higher in DAA group compared to normal AD group (8.3 ± 2.7 vs. 5.4 ± 2.2 mm, p < 0.001) as well as age (53 ± 10 vs. 48 ± 9 years, p = 0.004), the presence of hypertension (54% vs. 30%, p = 0.009) and UA levels (6.0 ± 1.4 vs. 5.2 ± 1.1 mg/dL, p < 0.001). There was a strong correlation between EAT thickness and ascending aortic diameter (r = 0.521, p < 0.001). In multiple logistic regression analysis, EAT thickness (OR: 1.429, p = 0.006), body mass index (OR: 1.169, p = 0.014) and UA levels (OR: 1.727, p = 0.023) were independently correlated to ascending aortic dilatation. We therefore propose that increased EAT thickness is an independent predictor of ascending aortic dilation.