Background: Mediastinal and epicardial adipose tissues are correlated with several adverse metabolic effects and cardiovascular diseases, especially coronary artery disease (CAD). The manual measurement of these fat tissues is widely done in clinical practice due to its human efficacy. As a result, the automated measurement of cardiac fats could be considered one of the most important biomarkers for cardiovascular risks in imaging and medical visualization by physicians. Methods: In this cross-sectional study, 2 non-contrast computed tomography (CT) data sets were used. An algorithm was designed based on data from 20 patients for cardiac fat measurement. One hundred twenty patients were examined to determine the relationship between CAD and the volume of cardiac fats using coronary artery calcium scoring assessment. Results: In the examination of the correlation between CAD and the volume of cardiac fats, coronary artery stenosis was severe in 11 patients (9.2%), moderate in 15 patients (14.2%), and mild in 17 patients (14.2%); additionally, no coronary artery stenosis was detected in 77 patients (64.2%). Cardiac fat was measured with an accuracy of 99.2%, and the best threshold obtained an epicardial fat volume (EFV) of 140 mL and a mediastinal fat volume (MFV) of 94 mL for having the largest correlation. In addition, with the increment in the severity of CAD, there was a considerable increment in cardiac fat volume and a significant linear correlation between coronary artery stenosis and MFV (r =0.36; P <0.001) and EFV (r =0.322; P <0.001). Conclusions: Cardiac fat tissues could be utilized as a trustworthy biomarker tool to predict the extent of CAD stenosis. (Iranian Heart Journal 2021; 22(3): 53-63)