Alkaline esophagitis is a postoperative complication of a gastrectomy due to gastroesophageal reflux. A lymph-node dissection around the abdominal esophagus, a truncal vagotomy, and dissection to the phrenoesophageal membrane are performed during a radical subtotal gastrectomy, resulting in anatomical and functional changes in the lower esophageal sphincter which is an important structure in the antireflux mechanism. This study evaluated the changes in the esophageal functions and the degree of esophageal reflux before and after a radical subtotal gastrectomy.Ten patients with a relatively early stage of stomach cancer were included, and esophageal manometric studies were performed on all patients before and after the radical subtotal gastrectomy. The pressure and the length of the lower esophageal sphincter and the function of the upper esophageal sphincter were measured. In addition, 24-hour ambulatory esophageal pH monitoring was done before and after the radical subtotal gastrectomy to obtain the percent of the total time for which pH<4, pH>7, and pH>8 and the pre-and post-operative values were compared. There was no significant difference between the pressure and the total abdominal length of the lower esophageal sphincter before the radical subtotal gastrectomy and those after the operation. The pressure in the lower esophageal sphincter was slightly decreased after the operation, but fell within the normal range (pre-op.: 19.7 3.2 mmHg; post-op.: 15.9 5.4 mmHg). There was no increase in the percent of the total time for which pH<4 and pH>8 in the 24-hour ambulatory esophageal pH monitoring. In conclusion, functional changes after a subtotal gastrectomy and alkaline reflux might not be affected by the anatomical derangement due to the surgical procedure itself.