BACKGROUND/AIMS To investigate the effects of preoperative pancreatic function on gastric emptying, body weight, and quality of life after pylorus-preserving pancreatoduodenectomy. METHODOLOGY Thirty-one patients who underwent pylorus-preserving pancreatoduodenectomy were divided into 2 groups according to preoperative pancreatic exocrine and endocrine function (normal vs. abnormal). Gastric emptying, body weight, and quality of life were evaluated before surgery, 1-2 months after surgery (short-term), and 6-12 months after surgery (long-term). RESULTS Short-term body weight was significantly decreased in comparison to preoperative body weight regardless of preoperative exocrine and endocrine pancreatic function. Body weight returned to the preoperative level by 12 months after surgery in patients with normal preoperative pancreatic function but not in patients with abnormal pancreatic function. In both groups, gastric emptying was delayed at 1-2 months after surgery and then returned to the preoperative value by 12 months. Short-term quality of life did not differ from preoperative quality of life in either group, but long-term quality of life improved to beyond the preoperative level in both groups. CONCLUSIONS Preoperative pancreatic function appears to significantly influence long-term body weight after pylorus-preserving pancreatoduodenectomy.