Hypertension is one of the components of the metabolic syndrome. The “deadly quartet,” as this syndrome is often referred to, also includes atherogenic dyslipidemia; hyperglycemia and/or insulin resistance (IR); and abdominal obesity. More than 47 million people in the United States have the metabolic syndrome, with a higher prevalence in certain ethnic groups. This is expected to rise significantly in the future, in large part due to the obesity epidemic. The relative contribution of each of the constituents of this syndrome varies according to the population in which it occurs, but the significance of these variations is not known. In this article, we review the role of hypertension in the metabolic syndrome, its complex association with obesity and IR, and its disproportionate contribution to the syndrome in certain ethnic groups (specifically US blacks).