An asymptomatic 56-year-old woman, upon medical examination, was diagnosed with advanced adenocarcinoma of the upper third of the stomach. Computed tomography showed that the primary gastric tumor was directly invading the splenic hilum, and there were multiple metastases in the spleen; incurable gastric cancer was confirmed. S-1 plus cisplatin therapy was introduced as the induction regimen, and the main tumor and splenic metastases reduced significantly. Total gastrectomy with splenectomy and D2 lymphadenectomy was performed after 9 courses of chemotherapy. The surgery was completed with no residual tumor, and intraperitoneal washing cytology was negative. Histologically, the primary tumor was classified as Grade 2, reflecting the effect of chemotherapy, and viable metastatic tumors were confirmed in the spleen. S-1-based treatment was continued as adjuvant chemotherapy, and the patient was alive with no evidence of tumor recurrence 39 months after the initiation of chemotherapy. Although metastasis to the spleen from gastric adenocarcinoma has been reported as a rare metastatic pattern with poor prognosis, our patient had a long survival time after gastrectomy following induction chemotherapy.