OBJECTIVE To describe clustering of hypertriglyceridemia, low HDL cholesterol, hypertension, diabetes, and hyperuricemia and its association with fasting insulin, waist-to-hip ratio (WHR), and BMI for African-American and white men and women. RESEARCH DESIGN AND METHODS Observed frequencies of clusters were compared with those expected in 14,481 participants, 45-64 years of age, of the Atherosclerosis Risk in Communities (ARIC) baseline survey, 1987–1989. Associations of clusters with insulin, central adiposity, and overall obesity, as well as with abnormalities, were analyzed through multiple logistic regression. RESULTS Clustering beyond chance was observed in all four sex/ethnic groups (P < 0.001), with 7% of the sample presenting 30% of the abnormalities in large clusters (≥ 3 abnormalities per individual). The odds ratio (OR) for the association of each abnormality with clustering of the remaining four ranged from 1.6 to 8.8 (P < 0.01). These odds of clustering were notably large in white women. Of the abnormalities, hypertriglyceridemia demonstrated the highest OR (5.0–8.8) and diabetes had the lower OR in African-American subjects than in white subjects (P < 0.001). Insulin, WHR, and BMI were statistically associated with clustering in all groups (P < 0.001, except for BMI in African-Americans. CONCLUSIONS Clustering of abnormalities consistent with the concept of a metabolic syndrome is present in both white and African-American subjects.