This study evaluated the ability of ultrasound measurement of subcutaneous adiposity to accurately determine whole body and segmental body fat in young adults aged 18-29 years. Subcutaneous adipose tissue (SAT) thickness was measured by ultrasound at five body sites in 135 subjects (83 men, 52 women) and compared with the corresponding segmental fat mass measured by dual energy X-ray absorptiometry (DXA). Ultrasound measures of SAT thickness were strongly correlated to segmental fat mass and total percentage (\%) body fat (r=0.697-0.907, p \textless 0.01). Prediction equations generated using quantile regression found SAT thickness at the abdomen and thigh to accurately predict \% body fat in men (standard error of the estimate, SEE=1.9\%