The four main clinicopathological subsets of melanoma are described and the arguments for their retention in a research setting presented. Further additional subsets are described, including partly regressed primary melanoma, melanoma arising in a congenital naevus and multiple primary tumours. Pathological prognostic indicators are discussed and the pre-eminent significance of tumour thickness and its interaction with ulceration described. The need for accurate personal predictive profiles as distinct from those relevant to populations is discussed, as is the need for a molecular marker of metastatic potential.