Angiosarcoma represents only 2.4% of soft tissue malignancies. Primary angiosarcoma of the breast is also a rare neoplasm. The incidence of this disease has been reported to be 0.04% of all breast malignancies. The aetiology is unknown. Angiosarcoma associated with chronic lymphoedematous arm of a postmastectomy woman was described by Stewart and Treves. In this paper we describe a 62-year-old female who underwent wide excision, axillary node dissection and adjuvant radiotherapy for primary breast cancer. After 5 years she noticed a purple discolouration of the treated left breast. Biopsy of these areas confirmed an angiosarcoma. No haematogenous dissemination was found. She underwent simple mastectomy without systemic therapy. A chest X-ray 3 months later revealed diffuse bilateral lung metastases. The incidence of breast conserving therapies is growing fast. Until now we have no evidence on the role of irradiation as an aetiological reason for angiosarcoma after breast-conserving surgery and axillary node dissection. Therefore, we have to pay increasing attention to these patients. A patient with history of radiotherapy after breast conserving therapy and skin discolouration must undergo a biopsy of these areas. The only therapy of angiosarcoma is an early mastectomy. The success of chemotherapy is uncertain. Possibly adjuvant chemotherapy with actinomycin D for the group with poorly differentiated tumours appears beneficial. Prospective studies might help to resolve this question.