In 2002, the American Joint Committee on Cancer (AJCC) revised the staging system for cutaneous melanoma on the basis of a survival analysis of important melanoma prognostic factors. Features of the revised system include new strata for primary tumor thickness, incorporation of primary tumor ulceration as an important staging criterion in both the tumor (T) and node (N) classifications, revision of the N classification to reflect the prognostic significance of regional nodal tumor burden, and new categories for distant metastatic disease. These changes reflect evolving insight into melanoma arising from the results of numerous clinical investigations and database analyses. One of the most important recent changes in melanoma care is the establishment of lymphatic mapping and sentinel lymph node (SLN) biopsy as a highly accurate and minimally morbid technique for pathologic regional nodal staging. In this article, the salient features of the revised melanoma staging system are examined, with specific attention paid to its use in this era of lymphatic mapping and SLN biopsy.