Elevated serum triglyceride level is increasingly being recognized as an important indicator of cardiovascular risk. The distribution and correlates of serum triglycerides were examined in a biracial (black-white) community-based sample of 1342 young adults (30% black) aged 20-37 years. Triglyceride levels showed significant race (white>black) and sex (male>female) differences. Black females, despite their relatively increased body fatness, had lowest triglyceride levels. In terms of conjoint trait of dyslipidemia based on the National Cholesterol Education Program cutpoints, 9% of white males displayed high triglyceride (> or =200 mg/dl) in combination with low high-density lipoprotein (HDL)-cholesterol (<35 mg/dl). In comparison, none of the black females fell into this category. Serum triglycerides even at levels between 100 and 150 mg/dl were significantly adversely associated with risk variables of insulin resistance syndrome such as adiposity and visceral fatness measures, HDL-cholesterol, insulin, and systolic blood pressure, especially among whites. Visceral fatness as measured by waist circumference (except black males) and insulin were the major predictors of triglyceride levels. Overall, triglyceride levels above 150 mg/dl were associated with increased risk of hypertension (odds ratio (OR)=1.8, 95% confidence interval (CI)=1.8-3.0), type 2 diabetes (OR=3.1, CI=1.4-6.9), parental history of hypertension (OR=1.3, CI=1.0-1.8) and parental history of type 2 diabetes (OR=1.7, CI=1.2-2.3). Thus, serum triglyceride levels may be valuable in the assessment of cardiovascular risk during young adulthood.