We report a case of a granulocyte colony-stimulating factor (G-CSF)-producing gallbladder tumor associated with fever in a middle-aged female. Preoperative blood analysis showed leukocytosis with elevated levels of C-reactive protein and G-CSF. We resected the liver at S4a＋S5, with regional lymph node dissection and partial resection of the duodenum. Histology revealed undifferentiated carcinoma with spindle and giant cells and papillary adenocarcinoma. Immunohistochemistry revealed Stage IIIB G-CSF-producing gallbladder cancer. Postoperatively, leukocyte and serum G-CSF levels decreased to within normal limits. Adjuvant gemcitabine chemotherapy was administered for 16 months, and she has been recurrence-free for 48 months.