Melanoma is the most common cancer amongst us. It is the cutaneous tumour with the worst prognosis and its incidence is growing. Although possible overdiagnosis has been criticised, the reality is that, the death rate has gone up from 6,000 to 9,000 cases in ten years. In the USA, in concrete, it is the main cause of death amongst women between 19 and 50 years of age. According to specialists from the University Hospital and from the USA, early diagnosis guarantees cure in 99% of patients with melanoma. Factors that bear on the appearance of a melanoma are genetic predisposition and ultraviolet radiation. It is clear that exposure to the sun is a specific cause. More concretely, this causes mutations whereby the capacity of the melanocyte to recover after solar radiation is annulled. In this regard, those people who suffer from burns or blisters after high doses of sun demonstrate a greater capacity to develop a melanoma. Despite its high incidence, the rate of survival from a melanoma is high, thanks to the melanoma prevention campaigns which enable the early detection of the melanoma and, thus, guarantees the efficacy of surgical treatment of the tumour. A few years ago diagnosis of melanoma was based on clinical experience and on information provided by the aspect of the skin lesion. To this end, the ABCDE rule was followed: asymmetry of the pigmented lesion, border (edges) that are irregular, colour, diameter (more than 0.6 cm) and elevation of the lesion from the skin surface. The diagnosis is completed with surgical extirpation to define the precise malignancy of the lesion. The incorporation of dermatoscopic techniques has greatly enhanced the diagnosis of this cutaneous tumour. It involves the application of a substance to the skin which makes the corneal layer transparent. By means of a number of devices we can observe a pigmentation pattern and a series of structures not visible to the human eye. It is a very useful tool for differentiating pigmented lesions without recourse to surgery. Two advanced diagnosis techniques are currently being put into operation. One of these is reflectance confocal microscopy, enabling the selection of those edges that are badly defined and the precise orientation for the extirpation of the lesion. The other is the multiespectral digital dermatoscopy, capable of photographing the pigmented lesion, process the images and produce an exact diagnosis. The information is completed with a clinical study and enables the focusing of the most suitable treatment. It is expected that, within a year, this technique will receive the approval of the FDA (Food and Drug Administration of the USA) and will be available at health centres.