A 62-year-old man was seen at the hospital because of abdominal pain and poor appetite. Computed tomography revealed tumors in the pancreas and liver. On admission, peripheral leukocyte count was 14, 760/mm³ and serum CA19-9 level was elevated to 73U/ml. Liver abscess was suspected for persistent fever but puncture and drainage of the liver did not demonstrate the presence of pathogens or tumor cells. Because serum concentration of granulocyte-colony stimulating factor was elevated to 160pg/ml, the patient was operated on with a diagnosis of G-CSF producing pancreatic cancer. But only biopsies were done because multiple liver metastases were identified. Histopathologic diagnosis of the tumor was poorly differentiated adenosquamous carcinoma of the pancreas. Immunohistochemical staining showed that pancreatic cancer cells were positive for G-CSF mainly in the squamous portion. Despite postoperative chemotherapy with general administration of gemsitabin hydrochloride and intrahepatic arterial infusion of 5Fu, the patient died 6 months after the tumors were detected.