Breast cancer is the second most cause of cancer death in case of women. It is the major issue among women of both old and young age. Efforts have been made by clinicians and researchers to improve the breast cancer treatment because the traditional approaches have low specificity and some side effects. Nanotechnology is a hopeful way for breast cancer treatment. It is rapidly emerging field which provides a big platform for the diagnosis and treatment of cancer. The use of nanoparticles enhanced the circulation time and accumulation of drugs in tumor. Nanoparticles mediated drug delivery provides high stability, less toxicity and more loading capacity as compare to traditional chemotherapeutic drugs. In this chapter we will summarize the most recent therapeutic nanoparticle mediated Drug Delivery Systems (DDS) and their significance in breast cancer treatment.