Background The purpose of this study was to evaluate glycemic control in type 2 diabetes mellitus (T2DM) patients with coronary artery disease in China, as well as to look into therapeutic inertia among cardiologists. Methods From June 2021 to December 2021, a descriptive cross-sectional study was conducted in the Department of Cardiology at Shanghai Ruijin Hospital in China. The method of convenience sampling was used. Patients with coronary artery disease (including acute and chronic coronary syndrome) and T2DM were included in the study. Patients with renal insufficiency (eGFR 2), heart failure (left ventricular ejection fraction, LVEF