Exchangeable sodium, plasma renin activity, plasma angiotensin II and plasma aldosterone were measured in forty-six control subjects, nineteen patients with chronic non-cirrhotic liver disease and twenty patients with compensated cirrhosis (i.e. without ascites or oedema). In the three groups respectively, mean exchangeable sodium (mmol/kg lean body mass) was 53 (SD = 3), 50 (SD = 5) and 52 (SD = 8). Mean plasma renin activity (pmol l(-1) min(-1)) was 3.2, 3.1 and 3.0 supine and 6.2, 6.2 and 5.1 erect. Mean plasma angiotensin II (pmol l(-1) was 7.3, 5.8 and 6.6 supine and 10.6, 7.9 and 9.0 erect. Mean plasma aldosterone (pmol l(-1)) was 82, 64 and 77 supine and 188, 133 and 121 erect. There were no significant differences among the mean values of any of these variables. These findings indicate that, on the basis of exchangeable sodium measurements, sodium retention is not present in compensated liver disease and that the renin--angiotensin--aldosterone system is essentially normal.