Metabolic syndrome (MetS) is a clustering of cardiometabolic risk factors linked to insulin resistance and visceral obesity. Since 1988, when Gerald Reaven first described MetS as “Syndrome X,” an abundance of research has been undertaken on its pathophysiology, prognosis, implications, therapeutic strategies, and clinical relationships with other metabolic diseases. Experts have focused on MetS during the last few decades not only because of the increasing importance of obesity in the development of metabolic diseases but also because of the effect of MetS on mortality and the development of cardiovascular diseases. There are conflicting data on the association between MetS and mortality, with some studies showing an increase in mortality and others showing no increase in mortality. Most of the previously published studies that have investigated the relationships between MetS and mortality have been undertaken with subjects with a history of diabetes or hypertension included in the study population, since diabetes and hypertension qualify as individual components of the MetS definition. However, diabetes and hypertension may also be considered outcomes or endpoints of MetS. The presence of MetS increased the risk for all-cause mortality and the risk for CVD mortality in Asian people. These increased mortality attributed to the pre-existing diabetes or hypertension.