We report a rare case of breast cancer with cartilaginous and/or osseous metaplasia. A 59-year-old woman had a large lump in her left breast, which had enlarged gradually over a period of 2 years. Mammography, ultrasonography and aspiration cytology suggested phyllodes tumor with carcinoma. She underwent wide excision and sentinel lymph node biopsy. Because of the existence metastatic tumor cells in the sentinel lymph node on frozen section, sequential axillary lymph node dissection was conducted consequently. Histologically, the tumor consisted of invasive ductal carcinoma and spindle-cell carcinoma, including cartilaginous metaplasia. Adjuvant chemotherapy and whole-breast irradiation were performed. However, she died of multiple metastases to the liver 2 years after surgery. Breast cancer with cartilaginous and/or osseous metaplasia belongs to a special type of invasive carcinoma, and the incidence is very low. We here present our case and a review of the literature.