We reported three cases of patient with triple negative skin metastasis after mastectomy of breast cancer. All three cases had received radiotherapy for skin metastasis. Radiation therapy was effective for recurrent sites, and could improve patient's QOL. After radiotherapy, 2 patients died due to a distant metastasis. Case 1 was resistant to chemotherapy. Case 2 was no indication of chemotherapy because of dementia metastases. Case 3 was the only one continued chemotherapy. It appears that a further consideration was needed for the timing of radiotherapy to be performed among the treatments of locoregional recurrence and distant metastasis of breast cancer.