An alveolar soft part sarcoma(ASPS) is a rare malignant soft tissue tumor, which metastasizes to the lung, bone and brain. Recently, we encountered an unusual case of a metastatic ASPS to the bilateral breasts in a 27-year-old woman. She had undergone surgery for an ASPS in her right thigh two years ago, which metastasized to the breast on three occasions, 15 months, 20 months and two years after surgery.