The reliability of parietal cell vagotomy as a primary procedure for duodenal ulcer is still questioned by many, and several surgeons advocate pyloroplasty in certain subgroups. Since the opening of our hospital in 1972, a randomized, prospective study has been under way. Sixty-seven patients were randomized into three groups: truncal vagotomy and Jaboulay pyloroplasty (Group 1), parietal cell vagotomy and Jaboulay pyloroplasty (Group 2), and parietal cell vagotomy without drainage (Group 3). The overall operative mortality was zero, with an 18 percent morbidity. Postoperative Congo red testing revealed truncal vagotomy to be a more reliable vagotomy, with 25 percent of Group 1 patients noted to have some degree of incomplete vagotomy compared with 36 percent of patients in Group 3 (p less than 0.05). The ulcer recurrence in Group 1 was 4 percent, in Group 2 18 percent, and in Group 3 10 percent. No dumping or diarrhea was noted in Group 3 compared with Group 1 in which 4 percent of patients had dumping and 17 percent had diarrhea and Group 2 in which 14 percent of patients had dumping and 23 percent had diarrhea (p less than 0.05). The higher incidences of recurrence and postoperative side effects obviously related to the pyloroplasty made parietal cell vagotomy with pyloroplasty the least desirable operative procedure. Parietal cell vagotomy is technically a more difficult procedure, but if performed satisfactorily, results in greater patient satisfaction, with 81 percent of the patients symptom-free compared with 63 percent of those who had truncal vagotomy and pyloroplasty.