A 52-year-old woman was referred to our hospital because of upper abdominal pain. A computed tomography(CT)scan revealed bulky gallbladder and liver tumors. We reached a tentative diagnosis of invasive adenocarcinoma of the gallbladder and performed needle biopsy of the tumor. Biopsied specimens showed the proliferation of small round to oval cells with scanty cytoplasm and high rates of mitosis. Immunohistochemical examination showed that many tumor cells were positive for chromogranin A, synaptophysin, and CD56. Our final diagnosis was neuroendocrine carcinoma of the gallbladder with multiple liver metastases. The patient received cisplatin plus irinotecan chemotherapy. Remarkable shrinkage was observed after 3 cycles of chemotherapy, and a good response continued for more than 6 months. Gallbladder cancer patients generally have a poor response to chemotherapy, so we should be aware of the histopathological diagnosis of the cancer before starting treatment.