The metabolic syndrome is a common cluster of risk factors for coronary heart disease and type 2 diabetes mellitus that includes obesity, elevated blood pressure, insulin resistance, and dyslipidemia. The diagnosis of metabolic syndrome itself appears to be an important risk factor for atherogenic cardiovascular disease and diabetes, and there is recent evidence that its components cluster, rather than occurring together by coincidence. A recent statement from the American Heart Association and the National Heart, Lung, and Blood Institute slightly modifies and clarifies the diagnostic criteria for the metabolic syndrome that are most widely used in the United States, along with giving practical guidance about management. Prompt therapeutic attention to the underlying risk factors--abdominal obesity, physical inactivity, and atherogenic/diabetogenic diet--is warranted for all patients with the metabolic syndrome, and drug therapy for specific metabolic risk factors should be considered for those at high or moderately high 10-year absolute risk of atherosclerotic cardiovascular disease. A new class of investigational drugs that block cannabinoid type 1 receptors have shown promise. This review also discusses issues that require additional research and new drugs that are considered promising for treatment of the metabolic syndrome itself.