We study in a group of patients with endoscopically diagnosed duodenal ulcer (19; 17 males) and controls (11; 7 males) the gastric emptying of solids through scintigraphy and gastric acid secretion by standard tests. In the same way we investigated prospectively some clinical data, specially smoking habits. As a whole, patients with duodenal ulcer showed an emptying of solids slightly faster than controls (T 1/2-minutes-: 85.4 +/- 28.6 in patients with duodenal ulcer versus 116.9 +/- 46.5 in controls, p less than 0.03). However, most of our patients (15 of 19 or 79%) were found to have a normal emptying rate. No correlation was found between secretory outputs and gastric emptying. Smokers with duodenal ulcer had a faster emptying that non-smokers with duodenal ulcer (T 1/2 74.8 +/- 30.05 vs. 99.91 +/- 19.86; p = 0.05).