Pure primary squamous cell carcinoma of the breast is rare. Controversy exists as to whether a pure form exists or whether described cases represent extreme squamous metaplasia within an adenocarcinoma. We present a case of pure primary squamous cell carcinoma of the breast confirmed histopathologically with the absence of a distant primary tumor excluded using positron emission tomography. Because of the paucity of guidelines in the literature for this rare tumor, it is difficult to draw firm conclusions regarding the optimal treatment modality or the overall prognosis.