This is an interim report of a prospective, randomized study involving 194 consecutive patients who underwent elective operation for treatment of duodenal ulcer. The results of parietal cell vagotomy without drainage (PCV) and selective vagotomy-antrectomy and Billroth I anastomosis (SV-A-B I) were compared. There was no mortality. Postoperatively patients were examined at two, six, 12 months and every 12 months thereafter. The two operations showed no statistical difference in the frequency of diarrhea. Dumping was less (p < .01) after PCV than after SV-A-B I. Weight loss was less (p < .01) after PCV than after SV-A-B I. There were no recurrent ulcers after SV-A-B I and five after PCV. In each instance but one the recurrent ulcer healed on withdrawal of an ulcerogenic drug. One patient required reoperation. Reoperations in the PCV group consisted of one for recurrent ulcer, one for gastric outlet obstruction and three for intestinal obstruction. The reoperations after SV-A-B I consisted of four for gastric outlet obstruction, three for intestinal obstruction, one for ruptured spleen and two for incisional hernia. PCV was technically feasible and practical to perform except in the occasional patient with severe pyloric stenosis. Obesity was never a deterrent. After PCV it is reasonable to assume that a recurrent ulcer rate in the range of 5-10% can be expected by surgeons who have been properly trained. This recurrence rate is higher than that after SV-A-B I but no higher than that encountered with TV-P. The recurrence rate is acceptable and is a fair exchange for the avoidance of dumping and weight loss that accompany SV-A-B I with significantly greater frequency and which on occasion can produce gastric crippling, although this did not occur in this study. All recurrent ulcers after PCV do not require reoperation but when operative treatment is required the patient has all the options that he had prior to PCV.