The pathophysiological relevance of the metabolic syndrome is not currently understood, particularly when attempting to apply the diagnosis to children with varying degrees of adiposity or from ethnically diverse populations. The aim of this study was to evaluate the applicability of the metabolic syndrome characterization when the associations are explored by sex, race/ethnicity, and weight status. Participants were 247 multi-ethnic (African American (AA); n=90; European American (EA); n=102; Hispanic American (HA); n=55) children aged 7-12y. Anthropometric measurements, body composition, blood pressure and fasting blood samples were obtained. Approximately 9% of the children met the criteria for a clinical diagnosis of the metabolic syndrome. There were no differences in prevalence by sex, nor were there differences between girls and boys for mean values of each component. However, there were ethnic differences in characterization of having the metabolic syndrome, with HA more likely to meet the criteria. HA had greater waist circumference, higher triglyceride and glucose concentration and lower HDL-C concentration; whereas AA had higher blood pressure. Weight status was also positively associated with mean values for each component. Due to inherent variations in body composition, physiology and genetics, the usefulness of a characterization of the metabolic syndrome may be limited in the pediatric population.