Predictive equations estimate total fat mass obtained from multiple-site ultrasound measurements; however, the predictive equation of total fat mass has not been investigated solely from abdominal subcutaneous fat thickness.To develop regression-based prediction equations using abdominal subcutaneous fat thickness for predicting fat mass, and to explore the validity of these predictive equations.Cross-sectional study.Twenty-seven males and eighteen females were randomly divided into two groups as the model prediction and the validation. Total body fat mass was determined by dual-energy X-ray absorptiometry. The linear regression analysis was used to predict equations for total body fat mass from abdominal subcutaneous fat thickness acquired by ultrasound. Then, these predictive equations were tested on the validation group. Lin's concordance correlation coefficient (CCC) was used as a further measure of agreement.When fat mass prediction equations were tested on the validation groups, measured- and estimated-total fat masses in males (p=0.9) and females (p=0.5) were found similar. A good level of agreement between measurements in males (CCC=0.84) and females (CCC=0.76) was attained.The abdominal subcutaneous fat thickness obtained from a single region by ultrasound might provide a non-invasive and quick evaluation.