A considerable percentage of breast cancer patients who have undergone an axillary lymph node dissection (ALND) experience postoperative complications, with lymphoedema occurring most frequently. Axillary Reverse Mapping (ARM) is a new technique in which the lymphatic drainage system of the upper extremity can be visualized during an ALND. If lymphoedema is caused by severing of the lymphatic drainage system or removal of its associated lymph nodes, the preservation of these structures should reduce the incidence of lymphoedema. Patients who might benefit from ARM are patients for whom a subsequent ALND is indicated following a positive sentinel lymph node diagnostic procedure, and perhaps also patients who have an indication for a primary ALND following neo-adjuvant chemotherapy. A multicenter RCT is to start in the near future, during which we will investigate whether the preservation of axillary lymph nodes results in reduced morbidity.