Visceral fat tissue is an important predictor of cardio-metabolic diseases, carrying more risk than general fat accumulation. Epicardial fat, a particular form of visceral fat deposited around the heart, is considered an important cardiovascular risk predictor, in view of producing and releasing several adipo-cytokines. There is growing evidence about the physiological and metabolic importance of epicardial fat. Epicardial fat thickness and volume have both strong correlation between obesity, impaired fasting glucose, insulin resistance, metabolic syndrome, hypertension, diabetes mellitus, and atherosclerosis. Epicardial fat can be assessed by transthoracic echocardiography, cardiac magnetic resonance imaging, and computed tomography. In this article, we reviewed the anatomy, physiology, function, and the methods of assessment of epicardial fat tissue. We also have tried to discuss its relationship to metabolic syndrome and coronary atherosclerosis in the lights of recent findings.