Esophageal scintigraphy is a sensitive test for evaluating esophageal emptying. Use of this test in combination with gastroesophageal scintigraphy should provide useful information about esophageal and gastroesophageal function, which should be of great clinical value to both the clinician and the investigator. Gastroesophageal scintigraphy is the most sensitive noninvasive test for detecting gastroesophageal reflux; its permits quantitation of reflux; the technique is simple and rapid, and can be completed in 5 minutes in any nuclear medicine section equipped with a gamma camera. It is the first quantitative test of reflux and is useful in measuring the effectiveness of various therapies. Variations of the technique have been applied to detecting reflux and pulmonary aspiration in infants and children.