A 73-year-old female was referred from a local clinic with abdominal pain. A diagnosis of gastric cancer(cT3, cN0, M0, cStage ⅡB)and acute cholecystitis was made. Distal gastrectomy, D2, and cholecystectomy were performed. Postoperative pathological examination led to a diagnosis of adenosquamous cell carcinoma(pT3, pN2, M0, pStage ⅢA). SOX therapy was administered as postoperative adjuvant chemotherapy. However, multiple liver metastases were detected. XP and DTX therapies were administered; however, there was a reduction in performance status. The patient died 10 months after surgery. Gastric adenosquamous cell carcinoma is classified as a specific type according to the Japanese Classification of Gastric Carcinoma(15th edition). This carcinoma accounts for 0.3 to 0.5% of patients undergoing gastric cancer surgery and is relatively rare. Its malignancy level is higher than that of gastric adenocarcinoma, and its prognosis is poorer.