Large cell neuroendocrine carcinoma of the gall-bladder is a rare disease in which the prognosis worsens with size. We report a case of large cell neuroendocrine carcinoma of the gallbladder in a 64-year-old woman who presented with a right upper quadrant mass whose longest diameter was 11.5 cm; the mass was initially considered to be unresectable because of probable invasion to the main portal vein and biliary tract. The patient received multi-modal treatment, consisting of intraarterial chemotherapy, three-dimensional radiation therapy, right trisegmentectomy, and gamma-knife irradiation (for brain metastases). She has survived for 69 months since the initial diagnosis and has shown no signs of recurrence at 35 months after the last gamma-knife irradiation for brain metastases. This result suggests that multimodal treatment including surgery, chemotherapy, and radiation therapy achieved a good response and led to long survival.