Gastric mixed adenoneuroendocrine carcinomas (G-MANEC) are rare malignancies with about 40 cases reported to date in English literature. Clinically, G-MANEC is characterized by aggressive behavior with rapid progression including a high incidence of regional and distant metastasis, leading to tumor-related death without any chance of surgical resection. Moreover, there is no uniform standard adjuvant chemotherapy for G-MANEC. Here, we report a case of G-MANEC with extensive liver metastases that gained survival benefits from neoadjuvant chemotherapy. A brief discussion of the biological behavior and treatment of G-MANEC is presented.