We report a case of triple negative spindle cell carcinoma of the breast, responsive to irinotecan chemotherapy. A 49-year old woman who had a tumor in the chest wall with a skin ulcer visited our hospital. After being diagnosed with triple negative spindle cell carcinoma of the breast, she underwent surgery, adjuvant chemotherapy, and radiation at the other hospital. Fourteen months after the surgery, she developed an ipsilateral breast tumor as a result of local recurrence. Since eribulin and paclitaxel plus bevacizumab chemotherapies were not effective, she was transferred to our hospital, and we administered irinotecan as third-line chemotherapy. Skin lesions and effusion were reduced and her quality of life improved for 4 months.