Primary small cell carcinoma of the breast is a very rare disease, and only a few case reports have described small cell carcinoma of the breast that responds to chemotherapy. Here, we report a case of primary small cell carcinoma of the breast that was treated with surgery and chemotherapy for postoperative local recurrence in the chest wall and metastasis to the liver. The metastatic lesions showed a partial response (PR) to carboplatin and irinotecan, but did not respond to subsequent Taxotere and doxifluridine (5'-DFUR) treatment. We then treated the metastatic lesions with CBDCA and etoposide (VP-16), and were able to stop disease progression. Small cell carcinoma of the breast is as aggressive as its pulmonary counterpart. Therefore, the best therapy for primary small cell carcinoma of the breast may be surgery followed by adjuvant therapy similar to that recommended for small cell lung carcinoma.