The patient was a 57-year-old man diagnosed with cancer of the pancreatic head. After treatment by heavy ion beam therapy, pylorus-preserving pancreatoduodenectomy was performed. The tumor was pT3, pN0, pM0, stage IIA. Sixteen months after the surgery, the patient was admitted to the hospital because he was vomiting blood. Hemorrhaging caused by failure of the cut end of the gastroduodenal artery into the elevated jejunum was confirmed by angiogram, and the hemorrhaging could be stopped by a transcatheter arterial embolization operation. Twenty-four months after surgery, the patient was readmitted because he was once again vomiting blood. Hemorrhaging from the elevated jejunum was suspected by hemorrhagic scintigram, but the source could not be identified on further examination, and the choice of treatment was difficult. The patient died on the 9th day after admittance to the hospital. Even on examination at autopsy, the source of the hemorrhaging could not be identified. No recurrence of cancer could be found. This has proven to be a perplexing case, in that hemorrhaging from the end of the routinely cut gastroduodenal artery occurred 16 and 24 months after heavy ion beam therapy and pylorus-preserving pancreatoduodenectomy for pancreatic cancer.