The objectives of the present study were to test whether the measurement of waist girth is better compared to other measurements of obesity to quantify the prevalence of the metabolic syndrome and to examine if obesity should be included among the diagnostic criteria. A cohort of 8,879 women and 23,145 men in the Cooper Center Longitudinal Study was used for this analysis. Percentage body fat, body mass index, and truncal subcutaneous fat were strongly correlated with waist girth and were comparable in identifying the metabolic syndrome prevalence with the National Cholesterol Education Program-Adult Treatment Panel III clinical criteria. Removing obesity measures from the diagnostic criteria of metabolic syndrome identified a smaller group of patients who were at higher risk for cardiovascular disease. Therefore, identification of patients with metabolic syndrome is useful but heterogeneous in its presentation which should influence short-term and long-term clinical outcomes.