The occurrence of an angiosarcoma of the residual breast after conservative surgery and adjuvant radiotherapy for early mammary carcinoma is a very rare event. In western countries only 57 cases have been published in the literature (5 in Italy) since the first described case in 1987. Radiotherapy seems to be the most important etiological factor in the development of the neoplasm. Diagnosis is often delayed, owing to the "benign" aspect of the lesion. The only effective treatment is residual mastectomy, because chemotherapy is ineffective. The prognosis is often dismal, because of the aggressive behaviour of the lesion in most cases. The case of a patient with a multicentric secondary angiosarcoma of the breast recently operated on is described.