Primary squamous cell carcinoma (SqCC) of the breast is a very rare tumor accounting for less than 0.1% of all invasive breast carcinomas. This is a very aggressive, hormone receptor negative and treatment refractory tumor with poor prognosis. We report a case of primary SqCC of the breast in a 72-year-old postmenopausal lady who presented with a lump in the right breast. The treatment of primary SqCC of the breast does not differ from other common histological types of breast cancer and may involve surgery, chemotherapy, hormonal therapy and radiation therapy. Clinical trials including large series of these rare tumors are needed to increase our knowledge and to improve patient's outcome.