The purpose of this study was to extend existing nuclear medicine techniques for the diagnosis of esophageal motor disorders. A standard homogeneous bolus of 99mtechnetium sulfur colloid in water was swallowed in the supine position under the collimator of a gamma camera linked to a microprocessor. Bolus transit was recorded at 0.4-s intervals, and the movie obtained was used to analyze transit in an objective manner. Ten normal volunteers and 30 subjects with dysphagia not related to mechanical obstruction were studied with this technique. Radionuclide transit studies detected a higher incidence of esophageal motor abnormality than manometry or radiology in the dysphagia group. In addition a definitive description of the functional problem was possible in most cases. Radionuclide transit is a safe noninvasive test and suitable as a screening test for esophageal motor disorders.