Many physiological factors can alter gastric emptying, and the role of gastric emptying in functional dyspepsia is controversial. The aim of this study was to assess the effects of different factors (age, sex, the degree of dyspeptic and irritable bowel symptoms, lactase deficiency, smoking habits, the use of antiinflammatory drugs, and H. pylori gastritis) on gastric emptying in patients with functional dyspepsia. The study population consisted of 83 patients with functional dyspepsia and 11 control subjects who underwent a standardized scintigraphic examination to study gastric emptying. This study detected no difference in gastric emptying between different subgroups with functional dyspepsia. There was, however, a slight tendency for delayed gastric emptying among patients with functional dyspepsia compared to controls. Intragastric distribution of the solid content was more distally located in smokers, and the solid lagtime was prolonged among antiinflammatory drug users. The gastric emptying of liquids was delayed among older patients. The subgrouping of dyspeptic symptoms is of minor importance with respect to gastric emptying. Habitual smoking and the use of antiinflammatory drugs are potent factors able to alter the gastric emptying of solids, but the role of H. pylori seems to be less important.