In the first article in this continuing medical education series we review controversies and uncertainties relating to the epidemiology and initial diagnosis of localized cutaneous melanoma (ie, stage 0, I, or II). Many of these issues are unsettled because of conflicting evidence. Melanoma incidence appears to be increasing, yet its basis has not been fully explained. Despite the advantages of early detection, the US Preventive Services Task Force does not recommend skin screening for the general population. Occasionally, biopsy specimens of melanoma will show histologic regression, but the prognostic importance of this phenomenon is uncertain. Some practitioners recommend obtaining a sentinel lymph node biopsy specimen for thin melanomas showing regression, although this histologic finding is not part of the staging system for thin melanomas. Our goal is to provide the clinician who cares for patients with (or at risk for) melanoma with up-to-date contextual knowledge to appreciate the multiple sides of each controversy so that they will be better informed to discuss these issues with their patients and their families.