In this chapter, we try to debate two of the most several controversial points about melanoma: the role of the ultraviolet (UV) ray exposure and the position of the sentinel node biopsy in the dermatological daily activity. It has been demonstrated as a direct relationship between UV exposure and the risk of developing melanoma, but it is also true that a chronic continuous UV ray exposure can develop a protective action. Nodal evaluation is one of the most important prognostic indicators to be considered for the patient outcome. The aims for which sentinel node biopsy is so often adopted can be summarized in three points: a detailed nodal staging, a regional disease control, and a possible overall improved survival. At present, many authors do not think that it let the overall survival grow; therefore, they suggest its use only to stage regional lymph nodes and accurately identify patients who could benefit through an early complete regional lymphadenectomy.