The effect on kidney function, vasoactive systems and ascites outcome of long-term treatment with propranolol plus isosorbide-5-mononitrate, a combined therapy proven more effective than propranolol alone in decreasing portal pressure in the cirrhotic patient, is unknown. Thirty cirrhotic patients who survived acute variceal bleeding and were treated with propranolol plus isosorbide-5-mononitrate were studied. Portal and systemic hemodynamics (n = 15), inulin clearance, free water clearance, plasma renin activity, aldosterone concentration and prostaglandin E2 excretion (n = 20) were measured before and after 3 mo of treatment. In addition, data on ascites outcome in the entire series after a mean follow-up of 9.6 mo were compared with those of 30 patients undergoing elective sclerotherapy and with those of 30 patients treated with propranolol alone matched for age, sex, presence of ascites, Child-Pugh class and mean follow-up length included in other randomized controlled trials. Combined therapy significantly decreased the hepatic venous pressure gradient and azygos blood flow. In addition, no changes in inulin clearance, free water clearance, plasma renin activity, aldosterone concentration and prostaglandin E2 excretion occurred, despite a mild decrease in mean arterial pressure. Moreover, no differences among the three groups of patients studied in ascites outcome were found. These results suggest that long-term treatment with propranolol plus isosorbide-5-mononitrate does not impair kidney function, vasoactive systems or ascites outcome in cirrhotic patients.