The body composition of 99 men and 89 women from south India was estimated using hydrodensitometry, bioelectrical impedance and skinfold thickness. Comparisons of the hydrodensitometry (reference method) and skinfold methods showed that there were no significant differences between the methods, for estimates of fat free mass (FFM) and per cent fat. The mean difference between the estimates FFM (bias), from skinfold measurement and hydrodensitometry was small for both groups (+0.16 +/- 1.09 kg in men and +0.67 +/- 0.9 kg in women). The same trend was observed in per cent fat estimates (-0.37 +/- 2.04 in men and -1.49 +/- 2.28 in women), showing that the skinfold method can be used as an accurate and expedient method to determine body composition. The bioelectrical impedance method obtained a significantly lower FFM and higher body fat than the reference (hydrodensitometry) method. This could have been due to the use of an inappropriate equation derived from Western population studies. Hence, a new predictive equation, for the measurement of FFM by the bioelectrical impedance method was derived for this population, using the variables of height2/impedance and FFM measured by underwater weighing. The new equation for the bioelectrical impedance method then gave values of body composition which compared well (0.26 +/- 2.32 kg) in men and (0.36 +/- 2.49 kg) in women with the hydrodensitometry method.