Associations between body fat distribution, measured by waist/hip circumference ratio (WHR), and plasma lipids and lipoproteins were examined in 74 grossly obese adolescents. WHR was positively correlated in adolescent girls with total triglycerides (r = 0.44, P less than 0.01), total cholesterol (r = 0.49, P less than 0.001), and LDL-cholesterol (r = 0.59, P less than 0.001). In adolescent boys no correlation was found for total cholesterol but there were correlations for triglycerides (r = 0.41, P less than 0.05), LDL-cholesterol (r = 0.49, P less than 0.001), HDL-cholesterol (r = -0.66, P less than 0.001) and the ratio cholesterol/HDL-cholesterol (r = 0.62, P less than 0.001). Waist/hip ratio was not correlated with BMI or percentual overweight in obese girls, but a significant association was found in obese boys for both (r = -0.46, P less than 0.03 and r = 0.53, P less than 0.02). These results indicate that in obese girls a prevalence of abdominal fat distribution is correlated with increased triglycerides, serum cholesterol and LDL-C. In male adolescents total cholesterol is only slightly influenced but HDL-C concentrations are lower and LDL-C and the ratio CHOL/HDL-C higher.