We report an exceptional case of primary breast angiosarcoma in a 58-year-old man. This is a very rare breast tumor (0.04% of breast tumors) which may be difficult to diagnose. Treatment is now standardized: radical mastectomy associated with adjuvant chemotherapy for grade III or poorly differentiated tumors. Prognosis is variable, depending on tumor size and histological grade. Diagnosis should be established as early as possible because the 10-year overall survival rate is 80% for low grade tumors and only 20% for high grade tumors.