In a prospective study, patients resected for benign ulcer disease 20 years previously were followed up. Of 100 patients operated with anterior gastro-jejunal anastomosis and entero-anastomosis 51 were examined with gastroscopy and multiple biopsies taken from the stoma and gastric fundus. Acute and chronic inflammation of varying degrees were general findings. Single or multiple polyp-like changes at the stomal ring were found in 4 cases and in one patient an asymptomatic low differentiated, adenocarcinoma was found. Intestinal metaplasia and cystic dilatation of the gastric glands were most frequently found in the stomal biopsies and less frequent in biopsies taken from the gastric fundus. In order to evaluate these possibly precancerous changes all patients will be continuously controlled. Nineteen patients were dead at the time of the follow-up. One of these had died of carcinoma of the gastric remnant.