The postoperative results of pylorus-preserving gastrectomy (PPG) for gastric ulcer performed in 134 patients during the past 25 years (mean postoperative period, 16.6 years) were studied. The incidence of postoperative complications was low. Dumping syndrome occurred in only 4.4% and 0% of cases as assessed by questionnaire and interview, respectively. Four (5.4%) of 74 patients available for this study had ulcer recurrence. In one of these four patients concurrent gastroduodenal ulcer was suspected from preoperative gastric analysis. The site of recurrence was found in all cases to be the remnant antral gland area along the greater curvature between the proper gastric gland area and the duodenum. Basal and maximal acid outputs at the time of relapse were significantly higher in patients with recurrence than in patients without recurrence. The fasting and postprandial serum gastrin levels were high in one patient with recurrence, whose antrum was preserved as long as 3 cm proximal to the pyloric ring; this was longer than that described in our original method of PPG. In two other recurrent cases the serum gastrin levels were not different from those in nonrecurrent cases. Immunohistochemical examination of the residual antrum showed no increase in the G-cell density in patients either with or without recurrence. These results suggest that the long-term quality of life of patients treated with PPG remains favorable. Recurrence rate can be further reduced if PPG is strictly indicated for gastric ulcer only and carried out by meticulous surgical techniques. In the pathogenesis of the ulcer recurrence the role of gastrin release from the residual antral mucosa seems to be limited.