Regional lymph node metastasis in advanced gastric cancer is common, whereas axillary lymph node metastasis (ALNM) is rare. We experienced a patient with a solitary ALNM in gastric cancer. A 48-year-old woman underwent curative distal gastrectomy for advanced gastric cancer (P0H0T3N3M0CY0, stage IV). Twenty-one months after the surgery, she complained of an asymptomatic left axillary tumor. Mammography and computed tomography (CT) scans showed the presence of tumors in neither breast nor lung. Fine-needle aspiration of the axillary tumor demonstrated poorly differentiated adenocarcinoma cells, which coincided with the cells of the resected gastric carcinoma. We diagnosed ALNM from gastric cancer and operated on the patient with radical left axillary lymph node dissection. One year after the reoperation, she has had no recurrence. We conclude that gastric cancer can metastasize to unusual sites. A re-radical resection is recommended if curative resection is feasible.