Basal and food-stimulated levels of gastrin and pancreatic polypeptide (PP) were studied in 86 patients with non-ulcer dyspepsia (NUD), defined as chronic or recurrent epigastric pain without anatomical antecedents and without concomitant symptoms of irritable bowel. Thirteen patients with endoscopically confirmed duodenal ulcer disease (DU) and 13 healthy subjects constituted the reference groups. The mean basal gastrin concentration was moderately but significantly (p less than 0.05) higher in the NUD group than in the reference groups (24.3 +/- 1.6 (SEM) pmol/l in NUD, compared with 15.0 +/- 1.5 and 13.6 +/- 1.0 pmol/l among DU patients and healthy subjects, respectively). The well-established postprandial hypergastrinemia in duodenal ulcer patients could be confirmed in this study, and their gastrin response to food was significantly (p less than 0.01) greater than the responses observed both in healthy subjects and in NUD patients. The two latter groups did not differ significantly with regard to gastrin increments, but there was a tendency towards greater increases in the NUD group. A significantly (p less than 0.05) enhanced PP response to the test meal was observed among the DU patients, whereas the response pattern in NUD was closely similar to that in healthy subjects.