Insulin resistance is characterized by an impaired physiological response to insulin. The constellation of insulin resistance, and several other metabolic and vascular disorders, is known as the insulin resistance syndrome, or metabolic syndrome. The characteristic features of metabolic syndrome include; central obesity, hypertension, dyslipidemia and glucose intolerance, and abnormalities in both the endothelial cells and vascular function. Several studies have shown that insulin resistance is a predictor of coronary artery disease (CAD). Recent studies have described relationships between the entire constellation of components in metabolic syndrome and the risk of CAD. The increasing prevalence of the insulin resistance syndrome, and its strong association with risk of CAD, has highlighted the potential importance of its early diagnosis and aggressive treatment. The managements of metabolic syndrome include lifestyle interventions, aggressive treatment of the identified CAD risk factors, and the treatments of abnormal glucose tolerance and insulin resistance. The connection between insulin resistance, metabolic syndrome and coronary disease must be recognized, and it is important not only to manage the obviously apparent CAD risk factors, but also to identify and manage other sought factors.