We report a case of peritoneal metastasis of bile duct cancer that was successfully treated by surgical resection. A 70s man underwent pancreatoduodenectomy(PD)for bile duct cancer, and abdominal CT revealed a tumor in the peritoneum along the right kidney at 55 months after PD. As FDG uptake was seen at the lesion on PET-CT, he was diagnosed as recurrence of bile duct cancer or primary malignant tumor in the retroperitoneum. Because the tumor was solitary on CT and PET-CT, we conducted surgical resection of the tumor. Pathological diagnosis was well differentiated adenocarcinoma that was similar to the primary lesion, and the tumor was confirmed as recurrence of bile duct cancer. He remains alive without 2nd recurrence for 60 months since tumor resection(117 months since PD).