Gastric carcinosarcoma is very rare, and there is no standard chemotherapy regimen. We report a case of a 61-year-old woman with gastric carcinosarcoma associated with the liver and lymph node metastases. She underwent distal gastrectomy due to uncontrollable bleeding from the gastric tumor. Histopathological examination of the resected specimen revealed adenocarcinoma and sarcomatous component with spindle-shaped tumor cells accompanied by cartilage formation. She was diagnosed as carcinosarcoma of the stomach with distant metastases and underwent chemotherapy with S1–cisplatin. Although CT scan revealed shrinkage of the metastatic lesions after one course of the treatment, the lesions progressed after four courses. She underwent treatment with doxorubicin–ifosfamide as second-line chemotherapy and docetaxel as third-line chemotherapy. The metastatic lesions progressed rapidly and she died 9 months after diagnosis.