Abstract: Gastroesophageal reflux (GER) frequently exists in patients after surgery to remove carcinoma of the esophagus or cardiac cancer. Pressure above and below the anastomotic stoma in each patient was measured using a computerized esophageal manometer. Resting pressure above the stoma was higher than that below the stoma. A 24-hour pH monitoring demonstrated that GER does exist in these patients. Esophagitis and other abnormalities were found through endoscopy and pathological examination. The occurrence of GER with stapled anastomosis is similar to that of manual anastomosis. If GER occurred postoperatively, it was unlikely to recede over time. Twenty-four hour pH monitoring is the most reliable method for detecting GER. Sleeping in a semi-reclining position is an effective method for preventing GER in postoperative patients. It is important that treatments of GER include prokinetics and mucosal-coat protectants.