In a study on the abdominal fat deposition measurements were carried out with computed tomography (CT) at the umbilical level in 130 patients (68 males and 62 females), submitted to the Department of Radiodiagnosis for routine CT of the abdomen. Weight, height, waist and hip circumference were measured. From a single CT scan at the umbilical level the subcutaneous and intra-abdominal fat areas were calculated. In men relatively more fat was found in the abdominal cavity than in women. Using all possible subset regression for both subcutaneous and intraabdominal fat areas, the best subsets of predictor variables were examined for males and females separately. Quetelet index and hip circumference were good predictor variables, explaining more than 70 per cent of the variance of the subcutaneous fat in both males and females. Waist and hip circumference explained about 74 per cent of the variance in intra-abdominal fat in males and 56 per cent in females. The results indicate that the single CT scan is fairly representative of overall abdominal fatness and that waist and hip circumference measurements can provide a useful indication of the abdominal fat deposition.