We report a case of postoperative liver metastasis of pancreatic cancer that was resistant to S-1 and gemcitabine (GEM) successfully treated by hepatic arterial infusion of 5-fluorouracil (5-FU) and cisplatin (CDDP). A 70s woman was referred to our hospital for treatment of a pancreatic head cancer in November 2007. Pancreaticoduodenectomy with a regional lymphadectomy was performed in December 2007 and the pathological stage was Stage IVa. Adjuvant chemotherapy of UFT was administered one month after operation. However, a second chemotherapy of S-1 was administered because DUPAN-2 levels showed a high range 8 months after operation. Ten months after operation, abdominal computed tomography demonstrated a 2 cm tumor in the liver. Although, we performed a systemic GEM infusion and a combination of GEM and S-1, the liver metastasis had progressed. Then, hepatic arterial infusion (HAI) chemotherapy of 5-FU/CDDP was instituted weekly. This efficacy maintained a Partial Response from the start of HAI to the fifth month. She is alive to date, maintaining a stable tumor growth of 30 months after surgery. We suggest that HAI chemotherapy of 5-FU+CDDP might be an effective treatment to liver metastasis of pancreatic cancer and prolong prognosis of those patients.