The effect of 5 mg of sublingual dinitrate isosorbide (DNI) on the esophageal emptying of a semi-solid test meal labeled with 99mTc-sulfur colloid was studied by a scintigraphic technique in 18 chagasic patients with megaesophagus. DNI significantly reduced the esophageal retention measured at 0, 5, 10, 15, and 20 minutes after the end of the test meal ingestion. Five minutes after the meal not preceded by DNI the esophageal retention was always higher than 10% whilst 5 minutes after the meal preceded by DNI the retention was lower than 10% in 10 patients. These results indicate that DNI may be useful to reduce esophageal retention in chagasic megaesophagus.