Background Pancreatic fistula is a common complication after pancreaticoduodenectomy, which could be caused by: soft pancreatic tissue, pancreatic duct diameter 2. Here we report a case of pancreatic fistula due to obstruction of the jejunal loop due to compression of the jejunal loop by the superior mesenteric vessels. Case presentation A 68-year-old man was admitted to our ward due to intermittent epigastric distension and pain. After various examinations and treatments, he was diagnosed with middle bile duct cancer. Pancreaticoduodenectomy was performed, and pancreaticojejunostomy and hepaticojejunostomy were completed by lifting the jejunal loop from behind the superior mesenteric vessels to the upper region of the colon. On postoperative day 9, the patient developed acute diffuse peritonitis, and on postoperative day 10, the patient underwent a second exploratory laparotomy, during which it was confirmed that the pancreatic fistula was caused by obstruction of the jejunal loop due to compression of the jejunal loop by the superior mesenteric vessels, then the patient recovered and was discharged alive after retrograde drainage in the jejunum. Conclusions The superior mesenteric vessels after pancreaticoduodenal surgery can compress the jejunal loop and cause obstruction leading to serious complications, and it is recommended that general surgeons should avoid lifting the jejunal loop from the posterior aspect of the superior mesenteric vessels to complete the anastomosis.