Controversial data have been reported on gastric acid secretion in patients with chronic pancreatitis. Moreover, studies on gastroduodenal morphological changes in patients with this disease and with other alcohol-related conditions have given different results. Basal and penta-gastrin-stimulated gastric secretion, histological changes of gastric and duodenal mucosa, and basal and meal-stimulated gastrin were measured in 21 patients with chronic alcoholic pancreatitis and in the following pair-matched groups: 21 chronic alcoholics and 21 control subjects (nonulcer dyspepsia), and in 19 patients with proven liver cirrhosis of alcoholic origin. No patient suffered from peptic ulcers. Moreover, gastric secretion was also measured in 51 patients with proven duodenal ulcers and in 34 healthy subjects. Basal acid output in patients with chronic pancreatitis was significantly higher (p less than 0.05) than in the other groups, except for the patients with duodenal ulcers. Peak acid output values in patient with chronic pancreatitis were similar to those measured in patients with duodenal ulcer, and they were higher than in the healthy subject group and in patients with liver cirrhosis, but statistical significance was not attained for patients with nonulcer dyspepsia. An increased frequency of duodenitis was found in patients with chronic pancreatitis, whereas an increased frequency of gastric metaplasia in the duodenal bulb was observed in all the patients with alcohol-related conditions considered. No relevant differences among the considered groups were found relating to gastric histological changes. Basal and meal-stimulated gastrin were similar in all the studied groups. This study suggests that in patients with chronic pancreatitis there is increased gastric secretion and probably an increased capacity for secretion of acid. Moreover, in patients with chronic pancreatitis, duodenitis seems to be frequent, but it probably is not directly related to chronic alcohol consumption.