Aim: To study interconnections between epicardial adipose tissue thickness (EATt), parameters of glucose metabolism/insulin, C-reactive protein (hsCRP), serum adipokines and severity of coronary artery disease (CAD) depending on the presence of diabetes mellitus type 2 (DM 2); to determine significant markers of CAD severity in patients with DM 2., Materials and Methods: The study involved 106 patients with CAD (m/f 64/42, 60.96.8 years), including patients with DM 2 (group 1, n=35) and non-diabetic patients (group 2, n=71). Severity of CAD was evaluated according to angiography data with calculation of Gensini Score (GS). EATt was assessed via echocardiography. Serum levels of glucose/insulin metabolism parameters, lipid fractions, hsCRP and adipokines were evaluated. Clinical parameters, including GS, did not differ between groups., Results: EAT thickness median was elevated in gr.1 (5.1 mm vs. 4.4 mm in group 2), while adiponectin levels were decreased (6.55 g/ml vs. 7.71 g/ml). Linear regression of body mass index and resistin levels on EATt was revealed in gr.1; in gr.2 EATt linearly increased with waist circumference increment when EATt6 mm. Linear regression of EATt on GS was revealed in gr.1 when EATt8 mm, while linear regression in the whole GS range was obtained for HDL-C and hsCRP levels., Conclusion: Study results demonstrate differences in mechanisms of deposition and functioning of epicardial and abdominal adipose tissue depending on the presence or absence of diabetic status. Patients with DM2 are characterized by the excessive EAT deposition and decrease of serum adiponectin levels compared to non-diabetic patients in the equal conditions. Independent markers of CAD severity in DM 2 are decreased HDL-C and increased hsCRP levels, but not EATt.