Pancreaticoduodenectomy is a complex operation that previously carried high postoperative morbidity and mortality, but the operative mortality has decreased recently due to improvement in operative technique and perioperative care. This paper analyzes the postoperative complications after 64 pancreaticoduodenectomies performed during the past 3years and Gmonths from August, l989 to February, 1993 in the Department of Surgery, Asan Medical Center. 1) Postoperative major complications developed in 12 patients(l8.8%), including 3 intra-ab-dominal hemorrhage(4.7%), 3 gastrointestinal tract bleeding(4.7%), 3 intra-abdominal abscess (4.7% ), 2 pancreatic leakage(3.1%), and 1 bile leakage(1.6%). 2) The complications requiring relaparotomy in 3 patients(l intra-abdominal hemorrhage, 1 gastrointestinal tract bleeding, 1 Pancreatic leakage) ended fatally in 1 patient who died of gastrointestinal tract bleeding. Therefore, the overall martality rate was 1.6 percent. 3) A1though most complications could be managed conservatively, early reintervention should be done in dangerous complications such as uncontrolled pancreatic leaks and massive intraabdominal or gastrointestinal bleeding. 4) Based on our data, pancreaticoduodenectomy can be performed safely by experienced surgeons and can be used widely for suspicious periampullary tumorous lesions.