A previously described method for evaluating the completeness of proximal gastric vagotomy (PGV), the intraoperative endoscopic Congo red test (ECRT), may allow for a more complete parietal cell denervation and thus result in a lower long-term incidence of postvagotomy ulceration. Of 20 patients undergoing PGV, 12 (60%) required further gastric denervation after intraoperative ECRT of the following sites: right gastroepiploic nerve (7), the nerve of Grassi (4), and the lesser curvature (3). Confirmation of completeness of PGV by the ECRT was easily performed and ensured intraoperative quality control. The routine performance of intraoperative ECRT during PGV may ultimately decrease the incidence of subsequent recurrent ulceration.