We herein report the case of a 65-year-old man who presented with an anaplastic carcinoma of the pancreas, producing granulocyte colony-stimulating factor (G-CSF). The patient's laboratory data showed an increase in his serum CA19-9 levels 1 year after he had undergone surgery for transverse colon cancer. Computed tomography (CT) showed a mass in the pancreatic head. Following a diagnosis of primary or metastatic pancreatic cancer, we performed the pancreatoduodenectomy. The postoperative course was uneventful. However, on postoperative day 28, he suffered a disturbance of consciousness and demonstrated hypercalcemia with elevated serum levels of parathyroid hormone-related protein (PTHrP). CT revealed multiple liver metastases and massive ascites. His serum Ca level decreased temporarily, and he subsequently died 58 days after the pancreatoduodenectomy. A pathological examination revealed pleomorphic-type anaplastic carcinoma of the pancreas. Immunohistochemical staining showed the tumor cells to be positive for G-CSF. To the best of our knowledge, there have been no reports of G-CSF-producing anaplastic carcinoma of the pancreas associated with humoral hypercalcemia of malignancy.