The management of newly diagnosed breast cancer includes axillary staging, as the axilla is the primary site of lymphatic drainage for most breast cancers. Axillary ultrasound (US) plays an important role in the initial imaging evaluation of women with both early-stage and locally advanced breast cancer. Identification of axillary metastases guides treatment decisions including recommendation for neoadjuvant chemotherapy (NAC), the choice of axillary surgery, and the decision of whether to proceed with adjuvant radiation therapy. As axillary surgery continues to evolve toward minimally invasive techniques with less morbidity, the value of axillary US in the patient with newly diagnosed breast cancer continues to grow. In this lecture, we aim to explain the staging of axilla by imaging in newly diagnosis breast cancer.