Here, we report a case of superficial-type gastric cancer with metastatic ovarian cancer(Krukenberg tumor)diagnosed by exploratory laparotomy. Chemotherapy was initiated at an early stage in this patient. A 43-year-old woman with superficialtype gastric cancer(0-Ⅱb plusⅡa), an ovarian tumor, and a solitary sclerotic bone lesion underwent exploratory laparotomy and bilateral salpingo-oophorectomy. Pathological findings showed that the resected ovarian tumor specimen contained the same type of signet ring cell carcinoma as the biopsy gastric cancer specimen; hence, the patient was diagnosed with superficial- type gastric cancer with metastatic ovarian cancer. She was treated with first-line chemotherapy(capecitabine plus oxaliplatin)15 days after exploratory laparotomy, followed by second-line chemotherapy(ramucirumab plus paclitaxel), thirdline chemotherapy(nivolumab), and fourth-line chemotherapy(irinotecan). Twenty-two months after the start of first-line chemotherapy, she finally died due to bone metastasis.