An early aggressive approach to screen and to manage the metabolic syndrome is of urgent need in Korea because of the recent nation-wide epidemic of the macrovascular disease and type 2 diabetes mellitus. Although the clinical definitions of the metabolic syndrome proposed by many organizations are still unclear in terms of the pathogenesis of the disease, those definitions are clearly valuable to identify those at high risk for diabetes mellitus and/or a cardiovascular event by clustering a number of easily measurable clinical findings. This article briefly reviews the debates on the definition and pathogenesis of the metabolic syndrome and highlights recent studies that demonstrate the effectiveness of therapeutic lifestyle changes and various drug trials in improving or preventing the components of the metabolic syndrome. The initial intervention should begin as early as possible with a healthy nutrition, daily physical activity, and appropriate annual screening. The initial step of intervention should be focused on the appropriate weight reduction goal with intensified lifelong lifestyle modifications, while it is not always enough and pharmacologic therapies are required in most patients. Weight reduction medications that can improve insulin sensitivity including biguanide and thiazolidinedion might be appropriate for the correction of the underlying pathogenesis of the disease.