Xeroderma pigmentosum is a rare genetic disease transmitted via a recessive gene with an altered reaction of the epidermis to light. Fifty per cent of patients develop a skin tumour by 8 years of age. The majority of patients may have multiple tumours, but metastasis is rare. In the last 25 years we have treated 24 xeroderma pigmentosum patients in our clinic. Only five patients had developed cutaneous malignant melanoma during their follow-up. Three of the patients were from the same family, melanoma occurring in three of five affected individuals. All xeroderma pigmentosum patients with malignant melanoma had received classical treatment modalities. Except one case of fulminant pattern, all four patients had long disease-free survival. Although early detection and treatment of these cutaneous malignancies will reduce morbidity and mortality, genetic counselling remains the most important protective measure for xeroderma pigmentosum.