Malignant melanoma (MM) is a frequent form of cancer with increasing incidence. 6-10% of patients with MM report a family history of MM, and in most populations 2% of unselected cases of MM carry a CDKN2A mutation. tvWe present a family with 24 cases of MM in nine persons from several generations, caused by a previously undescribed germ-line intronic mutation in CDKN2A. Through genetic counselling and genetic testing high-risk persons in the family are located and offered regular screening for MM.