Abstract: The authors report a case of primary osteosarcoma of the breast (POB) on ⁹⁹Tc^m-MDP whole body bone imaging. The characteristics of the disease were analyzed from the clinical symptoms, laboratory examination, ultrasound, CT and the whole body bone imaging. To summarize the imaging features of POB through literature review. POB is rare clinically, ⁹⁹Tc^m-MDP whole body bone imaging can help to find out the metastases, multifocal lesions, differential diagnosis and clinical staging of the disease, it has certain clinical significance.