Primary breast squamous cell carcinoma (SCC) is an extremely rare malignancy tumour. Reported case of this diseases only less than 0.1% of all breast carcinomas. SCC of the breast have aggressive histological features at presentation, and have poor outcomes or poor prognosis. Management therapy of primary breast SCC does not differ from other common breast cancer. Because this is a rare disease, the standard therapy has not been established and may involve surgery, chemotherapy, hormonal therapy and radiation therapy. Clinical trials are needed to improve patient’s outcome. This case of primary breast squamous cell carcinoma is reported in a 52-year-old women from Indonesia who presented with a lump in the left breast.