Breast angiosarcoma is a rare and aggressive tumor. The role of F-FDG PET/CT in breast angiosarcoma is poorly known. We report a series of 13 lesions in 11 patients with histologically proven primary or secondary breast angiosarcoma who underwent FDG PET/CT at the initial assessment in our institution. All breast lesions showed FDG avidity. Visually and statistically, we observed a significant difference of SUVmax uptake foci between primary and secondary breast angiosarcoma (Wilcoxon test P < 0.0046) and a significantly poorer prognosis for high SUVmax than those with low SUVmax (P = 0.049) regardless of primary or secondary origins.