Ultrasound-guided fine needle sampling is proving very useful for avoiding surgical biopsy of the sentinel lymph node for N+breast cancer. Because of its high specificity, cytology is sufficient in most cases. Focal or diffuse cortical thickening or the absence of the echogenic hilum irrespective of the size and shape of the lymph node are ultrasound signs which should be taken into account. The status of the lymph nodes in axillary and extra-axillary sites has an impact on the later management of patients and reduces the length of time for secondary lymph node dissection and adjuvant therapy, as one third of sentinel ganglion procedures can be avoided. It should be possible to optimise identification of the sentinel lymph node by the intradermal injection of ultrasound contrast agent. The cost/effectiveness ratio is positive but unknown and should be assessed in the initial management of breast cancer.