It has been reported that more than three-quarters of patients with dyspepsia were diagnosed to have functional dyspepsia. But the causes of this syndrome are unknown. Therefore, to evaluate the relationship between the gastric motor activity and functional dyspepsia, we compared the gastric emptying time (GET) in patients with functional dyspepsia with that in normal contrals. The study population consisted of 165 patients with functional dyspepsia admitted to or attending Hanyang University Hospital and 20 volunteers from the the beginning of Feb. 1989 to the end of June 1991. We measured gastric emptying rate for 150 minutes using radionuclide scintiscan of an Tc-labeled chicken liver. The m#ean GET (T1/2) was 84.9+-16.4 min in normal controls. In 165 patients, 94 patients (57%) showed delayed gastric emptying, whereas 71 patients (43%) showed normal gastric emptying. The median age for patients with functional dyspepsia was 41 years. Women outnumbered men in patients with functional dyspepsia (2:1). There were no statistical differences in scores of upper gastrointestinal symptoms. Gastric emptying time was delayed in 57% of patients with functional dyspepsia and women outnumbered men two folds. Also our results showed the.t the scores of upper abdominal symptoms cannot be helpful in diagnosing the underlying gastric motility disturbances.