Plasma concentrations of atrial natriuretic peptide (ANP), aldosterone (PA), vasopressin (AVP) and plasma renin activity (PRA) were measured in 15 patients with decompensated cirrhosis of the liver during a control period and subsequently during intravenous administration of albumin. Infusion of hyperoncotic albumin increased diuresis, natriuresis, stimulated ANP secretion and tended to normalize other vasoactive hormone levels in 9 patients (responders), whereas it had no effect in 6 other patients (non-responders). Responders had significantly lower basal levels of ANP and higher ones of PRA, and AVP than non-responders, suggesting that responders had decreased effective intravascular volume. Our data suggest that cirrhotic patients with ascites formation do not represent a homogenous group. In some patients with decompensated cirrhosis a compromised circulatory state with decreased effective circulatory volume induces compensatory changes in several regulatory hormones. It appears that secondary alterations in the plasma concentrations of ANP of cirrhotic patients may occur according to the suspected change of intravascular fluid volume.