Denmark is a high-risk country for malignant melanoma (MM).The incidence of MM has increased faster than the ones of any other cancer during the last ten years. 5-10% of the patients with MM report a family history of MM, and this is most likely caused by a combination of genetic and environmental factors. The genes disposing to MM are reviewed in this article and the challenges and ethical considerations concerning genetic counselling of families at high risk of MM are discussed.