Type 2 diabetes mellitus is a metabolic disease of carbohydrate metabolism. However, it should also be considered a vascular disease because diabetic patients have a strong predilection for atherosclerosis. With the increasing prevalence and earlier age at onset of diabetes, the projected effect of diabetes on cardiovascular health and resource utilization is sobering. The mechanisms of the high rate of atherosclerosis are multifactorial and give clinicians and researchers insights into potential preventive therapies. Effective pharmacologic and lifestyle interventions are available for primary and secondary prevention of cardiovascular complications. However, data show that these interventions continue to be underutilized. Treatment of patients with type 2 diabetes and coronary artery disease is similar to that of patients with coronary artery disease alone. However, patients with diabetes benefit more from treatments that reduce coronary artery disease risk.