Neurofibromatosis (NF) is a relatively common disorder characterized by cutaneous pigmented maculas, multiple neurofibromas and Lisch nodules (pigmented iris hamartomas). This disorder is retained being a neurocristopathy. Melanocytes are neural crest derivates too. Twenty-six patients with neurofibromatosis associated to cutaneous malignant melanoma have been reported till now, but data on association between these two pathologies are lacking. One more case of malignant cutaneous melanoma in a patient with neurofibromatosis is reported and the hypothesis of a more frequent association than usually believed of these two pathologies is discussed.