The aim of this study was to present our experience with primary breast angiosarcoma (PBA) by describing a large series of cases with an emphasis on clinicopathologic and radiologic correlations. Thirty-six cases of PBA diagnosed at our institution between 2006 and 2014 were retrospectively evaluated. All but one case occurred in women with a median age of 35.5 years. The majority of patients presented with a deeply located painless mass, whereas a minority manifested as diffuse enlargement or swelling of the breast. Magnetic resonance imaging showed poorly demarcated lesions with low signal intensity on T1-weighted images, markedly high intensity on T2-weighted images, and prolongation of enhancement upon dynamic study. Histologically, 19 cases (52.8%) were low grade, 12 cases (33.3%) were intermediate grade, and 5 cases (13.9%) were high grade. Follow-up information was available for 27 patients and revealed local recurrence and/or metastasis in 16 patients (59.3%). Five patients (18.5%) died of the disease at a median interval of 20 months. Univariate analysis showed that tumor differentiation had effect on disease-free survival (DFS) (p = 0.005) but failed to predict overall survival (OS) (p = 0.645). The treatment modality was related to OS (p = 0.042) but not DFS (p = 0.131). The Cox proportional hazards regression model suggested that tumor differentiation was an independent predictor of DFS (p = 0.015). We hypothesize that tumor differentiation may be used as a prognostic factor for this rare malignancy. Clinicopathologic and radiologic correlation may help pathologists to arrive at the correct diagnosis of PBA.