Background: We aimed to study the clinicopathologic and immunohistochemical (IHC) (CD117, c-Myc, and p53) characteristics, and overall survival of primary and secondary breast angiosarcoma (BAS). Methods: This was a retrospective study of BAS cases diagnosed between 1997 and 2020 at our institution. Hematoxylin and eosin-stained slides were reviewed for tumor morphology, margin status, and lymph node metastasis. CD117, p53, D2-40, CD31, and c-Myc IHC stains were performed on 11 viable tissue blocks. Additional clinical information was obtained from the electronic medical records. Results: Seventeen patients with BAS were identified. Of these, five (29%) were primary and 12 (71%) were secondary BAS, respectively. The median age at diagnosis for primary BAS was 36 years. The median age at diagnosis for secondary BAS was 67 years. The median time to secondary BAS development following radiotherapy was 6.5 years (range, 2 to 12 years). There was no significant difference between primary and secondary BAS in several histopathologic parameters examined, including histologic grade, necrosis, mitotic count, lymph node metastasis, and positive tumor margins. There was also no difference in CD117, p53, D2-40, CD31, and c-Myc expression by IHC between primary and secondary BAS. During a median followup of 21 months, primary BAS had two (40%) reported deaths and secondary BAS had three (25%) reported deaths. However, this difference in survival between both groups was not statistically significant (hazard ratio, 0.51; 95% confidence interval, 0.09 to 3.28; p = .450). Conclusions BAS is a rare and aggressive disease. No histologic, IHC (CD117, c-Myc, and p53), or survival differences were identified between primary and secondary BAS in this study.