The purpose of this study is to determine the hemodynamic effects of spironolactone administration associated with an unrestricted sodium diet (salt 10 g) in patients with compensated cirrhosis and portal hypertension. We studied the hemodynamic changes following eight weeks of administration of either placebo (N = 6) or spironolactone (100 mg/day) (N = 6 Pugh-Child's A and 6 B). No significant changes were observed after the administration of the placebo. Spironolactone induced a significant reduction in the hepatic venous pressure gradient (HVPG) (−10.1 ± 13.3%, P < 0.05), which was associated with a significant reduction of cardiac output (−11.5 ± 9.3%, P < 0.01), plasma volume (−8.1 ± 4.7%, P < 0.01), and wedged hepatic venous pressure (−10.5 ± 11.6%, P < 0.05). There was no significant change in hepatic blood flow and there was no significant correlation between the change in the HVPG and the change in circulating plasma volume. A decrease in the HVPG greater than 10% was observed in eight of 12 patients (67%), defined as responders, at eight weeks. Six of six (100%) grade A patients and two of six (33%) grade B patients responded. This study demonstrated that spironolactone with an unrestricted sodium diet decreased the HVPG in grade A patients but did not significantly decrease the HVPG in grade B patients.