We report a case of a 42-year-old female with occult breast cancer presenting axillary nodal metastasis. She complained of a swelling of the right axillary lymph node, but no breast mass was palpable. Biopsy of the lymph node was performed and histological examination showed a metastatic ductal carcinoma with papillotubular formation. Estrogen receptor of the lymph node was positive. No pathological findings were obtained by mammography and ultrasonography and systemic examinations revealed no extramammary primary lesion. All these data suggested an occult carcinoma of the breast and modified radical mastectomy was performed. Pathological findings of the removed specimen failed to find the primary breast cancer lesion. The patient has been treated with hormonal therapy and she is well without evidence of disease 5 years after surgery.