An 87-year-oldwoman was admittedto our hospital with abdominal pain andfever. Computedtomography showeda 25 mm tumor mass in the pancreatic headandshowedd ilatation of the pancreatic duct andcommon bile duct. She was diagnosed with obstructive cholangitis due to pancreatic head cancer. An endoscopic naso-biliary drainage(EUS)tube was inserted, and an endoscopic ultrasound(ENBD)examination was performed. At this time, duodenal perforation occurred, and an emergency operation was performed. During the laparotomy, perforation was found in the anterior wall of the duodenum. The contamination in the abdominal cavity and the degree of tissue damage in the duodenum were mild. Gall bladder jejunal andd uodenal jejunal anastomoses were performedfor biliary bypass andto close the perforation andbypass the gastrointestinal tract, respectively. She hadno postoperative complications andwas discharged 13 days postoperatively. Oral intake was possible after discharge, andthe patient returnedhome without complications. She died 5 months postoperatively. In this case, we performedbile duct andgastrointestinal bypass surgery prophylactically. Although this surgery will not be effective for all patients, we thought that it wouldbe useful for predicting the patient's future condition and for increasing the procedural options, even in case of emergency surgery.