A patient with intrapancreatic bile duct cancer underwent surgical reconstruction by the modified Whipple method following pancreatoduodenectomy. On the second day after the operation, the patient had to undergo reoperation because of suture failure at the location of the pancreaticojejunal anastomosis, when pronounced findings of peritonitis in the region were observed with detachment of the pancreatic duct tube. Since from the above findings it was judged that re-anastomosis was not possible, the pancreaticojejunal anastomosis was released, drainage tube was re-inserted into the pancreatic duct and the jejunal side was closed by suturing followed by full insertion of drainage tubes into the region. The patient's general condition was managed with complete fasting and intravenous alimentation for one month after surgery. Because of epigastric pain and decreased excretion of pancreatic juice after postoperative day 76, pancreatography was performed on day 80, revealing spontaneous internal fistulization, allowing drainage of pancreatic juice into the small intestine. The pancreatic duct tube was therefore removed. The patient showed a favorable clinical course and was discharged from hospital 6 months after the operation.