Anterior gastric seromyotomy combined with posterior truncal vagotomy has been proposed as an acid-reducing operation for patients with duodenal ulcer. Section of the posterior vagal trunk could, however, be held responsible for reduced pancreatic function, seen in patients after bilateral truncal vagotomy. In this study the pancreatic function after anterior gastric seromyotomy and posterior truncal vagotomy has been evaluated in a series of canine experiments by means of a direct hormone stimulation test. No reduction of the basal or stimulated exocrine pancreatic secretion was noted after this type of vagotomy.