The metabolic syndrome, also known as the dysmetabolic syndrome, syndrome X, or the insulin resistance syndrome, refers to the clustering of cardiovascular disease risk factors that are present in many individuals who are at increased risk for cardiovascular events and/or type 2 diabetes. The criteria for metabolic syndrome include a combination of categorical and borderline risk factors that can be readily measured in clinical practice. Although the Adult Treatment Panel III of the National Cholesterol Education Program set the criteria to identify cardiovascular risk, the syndrome had already been well recognized in the endocrine community as identifying people at risk for diabetes. Recently, the International Diabetes Federation proposed a worldwide definition with ethnic-specific criteria for waist circumference. Therapies targeted to specific components of the metabolic syndrome, such as improving glycemic control, managing dyslipidemia, and reducing the prothrombotic state, should help to minimize cardiovascular risk, particularly if initiated early.