There is no general agreement as regards the effect of Helicobacter pylori infection on gastric emptying in patients with functional dyspepsia. Food releases several gastrointestinal hormones, and some of these are known to contribute to the regulation of gastric emptying. The aim of this study was to investigate the influence of H. pylori on gastric emptying in dyspeptic and healthy subjects and to verify whether different hormone secretion patterns are affected by the presence of the bacterium. Twenty-seven patients affected by functional dyspepsia and 30 asymptomatic healthy subjects entered the study. H. pylori presence was assessed in controls by IgG antibodies to H. pylori and [13C] urea breath test, and that in patients by Warthin-Starry stain on gastric biopsies. After ingesting a standard solid-liquid meal, an ultrasound examination of gastric emptying was performed. Plasma concentrations of gastrin, cholecystokinin, and pancreatic polypeptide were measured in the fasting and postprandial period for 4 hours. The incidence of H. pylori infection was not higher in functional dyspepsia patients than in controls. As regards gastric emptying, no difference was detected between patients and controls with and without H. pylori infection. On the contrary, the presence of H. pylori infection determined alterations in gastrin levels, which were higher in controls than in patients. Basal CCK levels were higher in the H. pylori-negative patients than H. pylori-positive patients and controls. In conclusion, H. pylori infection seems not to cause alterations in gastric emptying, but rather alterations in gastrin levels. In contrast, the altered levels of CCK account for its involvement in the pathophysiology of H. pylori-negative dyspepsia.