Data from 514 adults participating in a population-based study in an Aboriginal community was used to determine the prevalence and determinants of metabolic syndrome, to compare three different criteria, and to assess the association of cardiovascular risk factors with the syndrome. The prevalence of the syndrome was 35% for NCEP, 33% for WHO, and 38% for IDF criteria. There was moderate to strong agreement among the three definitions. Older age, higher percent body fat, and lower fitness levels were associated with increased odds of the syndrome regardless of definitions and genders. Physical activity was independently related to the syndrome in men. Subjects with the syndrome had significantly higher leptin, C-reactive protein, and interleukin-6 levels and lower adiponectin levels, even adjusted for age and body fat. The findings suggested identification of the syndrome and early lifestyle interventions are important strategies in the prevention of diabetes and cardiovascular diseases in Aboriginal communities.