Metaplastic carcinoma of the breast (MCB) is a rare form of cancer containing mixture of epithelial and mesenchymal elements in variable combinations. Few and conflicting clinical data are available in the literature addressing optimal treatment modalities, prognosis and outcome. A retrospective study was conducted to review all patients with MCB diagnosed and treated at Breast Unit of Azienda Ospedaliera “Santa Maria” Terni - Italy between 2001/2010. The aim is to describe patient’s clinic pathologic features and to analyze treatment results. Six female patients were studied. The median age was 48 years (range 14/58). The median tumor size was 9 cm. (range 3/18 cm.). Two cases (33%) were identified as purely epithelial and 4 (67%) as mixed epithelial and mesenchymal metaplasia. Hormone receptors were positive in only 2 patients. Modified radical mastectomy performed in 3 patients and 5 underwent axillary node dissection. Adjuvant chemotherapy was given to all patients and postoperative radiotherapy to 4. Four patients relapsed with median time of relapse of 12 months. MCB is an aggressive form of breast cancer associated with poor outcome, high incidence of local recurrence and pulmonary metastases. The disease tends to be estrogen/progesterone receptor negative. Tumor size has an important impact on outcome. The best treatment approach is yet to be defined.