IntroductionPrimary angiosarcoma is a rare type of breast cancer. It is an aggressive tumour with a high propensity for metastasis. This article reports a case of primary angiosarcoma of the breast. Case reportWe report a case of a 24-year-old woman presenting with a painless mass arising in her right breast. Ultrasonography of the breast suggested phyllode tumour, but the diagnosis of primary breast angiosarcoma was confirmed only after detailed pathological examination and immunohistochemistry were carried out. Conclusion Primary breast angiosarcomas have a poor prognosis, with a poor longterm survival. Tumour size and tumour grade appear to be factors that affect the treatment outcomes for patients with primary angiosarcoma of the breast.