Angiosarcoma of the Breast is a tumor of blood vessels with low incidence which only represent less than 1% of all primary mammary tumors. It is most frequent within the third and fourth decade of live. Its clinical manifestation is highly varied and the diagnosis is usually late with a mortality rate reaching the 90% at the second year. This is a case report of a forty-nine years old woman who presented with a painless, palpable mass located in her right breast. A mammography was performed with no conclusive results which led to carry out a high-resolution ultrasound and a biopsy. The histological study reported low-grade Angiosarcoma which it is managed with surgical treatment and clinical observation. The report of this case is considered significant due to the absence of radiotherapy records previous to the appearance of the lesion, as well as the atypical clinical presentation, the low prevalence and the limited information available on this entity in our community.