The influence of 1000 ml of 0.9% NaCl infusion induced hypervolemia on the water-electrolyte and hormonal balance was investigated in HBV-infected patients with chronic persistent hepatitis, chronic active hepatitis and compensated cirrhosis. All examined patients showed higher concentrations of vasopressin and atrial natriuretic peptide and the increased activity of RAA system before the trial. The induced hypervolemia caused the decrease of RAA system's activity and vasopressin concentration and increase of atrial natriuretic peptide's secretion, different in every group of patients. The latent deficiency of calcium and magnesium was found, too. The results showed that all determined patients had water-electrolyte and hormonal disorders, significantly increased in patients with chronic active hepatitis.