Primary Sarcomas of the breast account for less than 1% of breast tumors. Leiomyosarcomas are less common. Only 51 cases have been reported in the literature, which only 4 cases in men. We present a new case of male breast leiomyosarcoma and discuss management and therapy of these unusual neoplasms. The confirmation of diagnosis was obtained by immunohistochemical study of surgical biopsy. The patient underwent a radical mastectomy and axillary lymphadenectomy. Adjuvant radiotherapy was indicated. Two years after surgery the patient is still in life without recurrence.