Background:Cardiovascular diseases (CVD) remain the leading cause of death worldwide. Among cardiovascular diseases, coronary artery disease (CAD) is the single largest cause of death.The epigenetic regulatory role of ncRNAs in CAD is still evolving. We aimed to investigate theplasma level of circ. ankyrin repeat domain36 (circANKRD36) in patients with CAD and type 2 diabetes mellitus(T2DM) Methods: A total number of 40 subjects with T2DM and 20 age and sex matched healthy controls were enrolled for the study. T2DM patients subdivided to T2DM without CAD (n=20) andT2DM with CAD (n=20)All patients were subjected to general and cardiological examination and investigation. Theplasma of circANKRD36 was measured using quantitative real-time (qRT) PCR. Results: The plasma levels of circANKRD36 were significantly increased in patients with CAD and T2DM compared to control. p˂0.001*. The plasma levels of circANKRD36 were significantly positive correlated with cardio metabolic risk factors and linear regression test revealed thatthat waist /hip ratio as well as SYNTAX score were independently correlated with epigenetic marker. Our results revealed that the cutoff values plasma levels of circANKRD36 were 1.735 and the AUC was 0 .877 (95% CI =0.790-0.963) additionally, the sensitivities and the specificities were 85% and 70%, Conclusion:T2DM groups had statistically significant higher values of circANKRD36 compared to control group. Plasma levels of circANKRD36 were significantly increased in T2DM patients with CAD compared with T2DM patients without CAD.Thus, it could be an epigenetic marker for prediction of CAD inpatients with T2DM.