Narrowing of the esophageal lumen often exists for months before being noted by the patient. Screening tests for such lesions would be useful, if applicable to office use. A magnetic disc tablet (14 mm in diameter and 5 mm thick) was fashioned by hand using dental acrylic material to enclose the magnet with a smooth watertight sheath. A magnetic detector was held on the anterior abdominal wall 2.5 cm below the xiphoid cartilage and 2.5 cm to its left. A significant change in reading indicated that the tablet had reached the cardia of the stomach. The magnetic tablet was readily detected in 11 patients without organic narrowing. Our method attempts to detect narrowing of the esophageal lumen by use of a magnetic disc tablet. Perhaps this will be of clinical usefulness in detecting esophageal disease before symptoms become apparent.