A ruptured pseudoaneurysm is the most serious and life-threatening cause of postpancreatoduodenectomy (PD) hemorrhages. We have evaluated the clinical course and management of pseudoaneurysms after PD. Of 586 patients who underwent PD for periampullary tumors in Asan Medical Center between March 2003 and March 2011, 27 experienced pseudoaneurysmal bleeding. Bleeding developed at a median of 21 days (range, 8 to 45 days) after surgery, including 9 patients who developed bleeding more than 4 weeks after surgery. Before development of bleeding, 26 patients showed pancreatic fistula. Bleeding was developed from the gastroduodenal artery stump in 12 patients, the common hepatic artery in eight, the proper hepatic artery in five, and the left hepatic artery in two. Of the angiographic group, 21 patients underwent with microcoil embolization, four underwent stent insertion, and one experienced technical failure. Only one patient required emergent laparotomy without angiography. Of 25 patients with angiographic procedures, all patients achieved hemostasis. The mortality rate was 22.2 per cent (6 patients). Delayed hemorrhage after PD is closely associated with pancreatic fistula and carried a significantly higher mortality rate. The patients with pancreatic fistula should be carefully monitored, even more than 4 weeks after surgery. Selective microcoil embolization or stent graft is effective for pseudoaneurysmal bleeding.