AIM: The aim of this study was to assess gastric slow waves, antral and duodenal motility simultaneously, and determine the correlation among all these measures in patients with functional dyspepsia. METHODS: Thirty-one patients with functional dyspepsia were assessed for severity of upper gastrointestinal symptoms with the electrogastrography (EGG) and antroduodenal manometry. The EGG and manometry were recorded for 3 to 4 hours in the fasting state and for 2 hours after a solid meal. Computerized spectral analysis methods were used to compute various EGG parameters. RESULTS: The EGG was abnormal in 71.0% of patients. The abnormalities included normal slow waves lower than 70% in the fasting state (51.6% of patients) and in the fed state (48.4% of patients), a decrease in dominant power in 28.9% of patients. Antral motility was abnormal in 80.6% of patients and duodenal motility was abnormal in 74.2% of patients. For the EGG and antral motility, 19 of 31 patients had both abnormal EGG and abnormal antral motility; 2 of 31 patients had both normal EGG and normal antral motility. For the EGG and duodenal motility, these values were 16/31 and 2/31, respectively. By both EGG and antroduodenal manometry, abnormal gastric motor function was found in 93.5% of patients. However, quantitative one-to-one correlation between any of the EGG parameters and the antroduodenal dysmotility was not noted. The patients showed high symptom scores particularly to upper abdominal pain, nausea, and belch. No one-to-one correlation was noted between the symptom scores and any of the EGG or motility parameters. CONCLUSIONS: More than two-thirds of patients with functional dyspepsia have abnormalities in the EGG and antral/duodenal motility. The sensitivity of these 2 different methods is essentially the same. EGG and antroduodenal manometry can complement each other in demonstrating gastric motor dysfunction in patients with functional dyspepsia.