Background: Hemosuccus pancreaticus (HP), a rare cause of upper gastrointestinal bleeding, is defined as hemorrhage from the duodenal papilla where blood comes via the pancreatic duct.We here first report one case of HP due to a fistula between splenic vein and main pancreatic duct.Case presentation: A 50-year-old man complained of recurrent episodes of hematochezia following acute abdominal pain during the preceding 3 years.The source of hemorrhage was not identified by digital subtraction angiography, contrast-enhanced computed tomography, magnetic resonance cholangiopancreatography, ultrasound and endoscope.Only endoscopic retrograde cholangiopancreatography showed blood spurting from the papilla of vater, suggesting HP.However, the laparotomy and intraoperative pancreatoscopy did not identify the source of hemorrhage.Our patient could not but undergo reoperation (total pancreatectomy).Examination of the resected specimen revealed a fistula between the splenic vein and main pancreatic duct which resultd in hemorrhage.During the follow-up period of more than three years, he is uneventful without recurrence.Conclusion: When we encounter intermittent upper gastrointestinal bleeding with an obscure source, HP should be included in differential diagnoses especially in patients with chronic pancreatitis and/or pancreatolithiasis.