1. Standard radioisotope dilution techniques employing [3H]water and [22Na]sodium chloride have been used to determine the total body water and total exchangeable sodium of 20 male and 10 female normal Ghanaians (Africans) aged 19–25 years.
2. Lean body mass and total body fat are calculated as a percentage of body weight; the total exchangeable sodium values have been expressed in relation to lean body mass.
3. Comparison of the data for Ghanaian subjects with published figures for Caucasian subjects of similar age shows that the Ghanaian men have much less total body fat and the women a little less total body fat than their Caucasian counterparts.
4. Total exchangeable sodium expressed in terms of lean body mass shows close agreement in both men and women.