Thirty-nine subjects have been studied: 14 with hepatic cirrhosis who had not been subjected to surgery, 13 cirrhotic patients in whom portacaval shunt had been performed, and 12 normal controls. In all of them, we performed serum determinations of pepsinogen I, both basal and after pentagastrin stimulation, and of basal gastrin levels, as well as analyses of basal and stimulated gastric acid secretion (basal acid output and maximal acid output). The values for pepsinogen I, basal or post-stimulation, were higher (p less than 0.001) in patients with cirrhosis who had not undergone surgical shunt than in those in the control group. However, there were no statistically significant differences when these two groups were compared with the patients who had been subjected to portacaval shunt. In this last group of patients, seven had levels similar to those of the controls, and six presented higher values. Likewise, the values for gastric acid secretion were similar in the three groups of patients, and the basal gastrin level was lower (p less than 0.001) among patients with liver cirrhosis, whether or not they had undergone surgery, than among the control population. In conclusion, the functional alterations of the gastric mucosa in patients with hepatic cirrhosis are not significantly different from those found in cirrhotic patients with portacaval shunt.