Satavaptan, a vasopressin V2-receptor antagonist, has been shown to improve hyponatraemia in patients with cirrhosis. Hyponatraemia has been associated with an increased risk of hepatic encephalopathy. The objective is to evaluate the efficacy of satavaptan in reducing the risk of new episodes of hepatic encephalopathy. 1,200 patients with cirrhosis and uncomplicated ascites were included in three randomised double-blind studies comparing satavaptan (5-10 mg/day) vs placebo over a one-year treatment period. Effects on incidence of hepatic encephalopathy episodes in individual study and pooled databases were determined with analyses adjusted for hyponatraemia and previous episodes of encephalopathy. Hyponatraemia was improved by satavaptan. Three hundred and ninety-five hepatic encephalopathy episodes were recorded. The risk of an episode and the mean number of episodes were not reduced by satavaptan in any of the three studies in the overall population or in patients who were hyponatraemic on entry. These findings were confirmed in analysis of the pooled data. Satavaptan did not reduce the frequency of hepatic encephalopathy in patients with cirrhosis and ascites.