We studied 76 patients with symptoms of heartburn, regurgitation, or both and 38 asymptomatic control subjects by measuring the gastric emptying of technetium-99m-labeled oatmeal. In addition, we performed 24-hour esophageal pH monitoring and manometric studies of the esophagus on all study participants. Endoscopy was performed on all patients. Patients with proved reflux on 24-hour pH monitoring, in comparison to those without reflux and the control subjects, had a shorter lower esophageal segment with a lower pressure and more esophagitis. Delayed gastric emptying occurred with equal frequency in patients with and without reflux. Esophageal reflux was not associated with delayed gastric emptying. Delayed emptying was associated with less esophagitis than found in those with normal gastric emptying, suggesting that the prolonged presence of food in the stomach may have a buffering effect on gastric acidity. We concluded that delayed emptying is not a major factor in the pathophysiology of gastro-esophageal reflux disease and that therapy aimed at speeding gastric emptying cannot be supported by our results.