A neonate was seen by the pediatrician because of a well-defined macular hyperpigmentation of the skin in the genital area. The diagnosis 'giant congenital melanocytic nevi (CMN)' was made. This occurs in 1 of 20.000 newborns. Children with giant CMN may develop neurocutaneaous melanosis of the central nervous system. They have an increased life time risk of 5% of developing melanoma.