Prostaglandin E2 (PGE2) tissue levels were measured, using radioimmunoassay, in specimens from the gastric antral mucosa in (a) healthy subjects, (b) patients without liver diseases in the absence or presence of gastric ulcers, and (c) patients with alcoholic cirrhosis in the absence or presence of gastric ulcers. These groups were divided further into subgroups with or without portal hypertension. PGE2 tissue levels in subjects without liver diseases were not significantly different from those of cirrhotic patients without portal hypertension. However, in cirrhotic patients with portal hypertension, the PGE2 content was significantly lower, especially in the presence of congestion in the mucosa (about 70-80%). When a gastric antral ulcer was present, a further statistically significant decrease of the PGE2 levels was observed. It was concluded that a decrease in the PGE2 tissue levels in the gastric mucosa of cirrhotic patients is related to the presence of portal hypertension. Congestion in the mucosa, as a pathogenetically relevant factor for mucosal PGE2 deficiency, may play a role.