The management of clinically normal regional lymph nodes in early-stage melanoma has been controversial for over a century. Lymphatic mapping and sentinel lymphadenectomy (LM/SL) has been developed as a minimally invasive surgical technique to stage the regional lymph nodes without the associated morbidity of elective complete lymph node dissection. Multiple retrospective studies have validated the accuracy of LM/SL and the importance of the sentinel nodes as a staging tool for melanoma. Two multicenter, prospective, randomized trials have been performed to validate the data from the Phase II studies and determine if a therapeutic benefit exists for LM/SL.