Breast metastasis from extra-mammary malignancy is rare, constituting 2% of breast tumors. Uterine leiomyosarcoma is a rare soft tissue neoplasm comprising 1% of all uterine malignancies. This report presents the first case of uterine leiomyosarcoma metastasis of the breast. A 44-year-old woman, G4P3AA1, presented with a one-week history of painless bilateral breast lumps. Twelve years previously she had undergone a right salpingo-oophorectomy and hysterectomy for uterine leiomyosarcoma. An excisional biopsy of the breast nodule was performed, and the histopathological study revealed the nodule was composed of spindle cells, typical of breast metastasis with uterine leiomyosarcoma found in the immunohistochemical study. The patient was healthy and symptom free during the 12 month post-operative follow-up period.