A number of interesting syndromes have been described in which skin tumors are markers of heritable disorders. In Cowden's disease, Muir-Torre's syndrome, and Gardner's syndrome, benign skin tumors accompany and sometimes precede the development of internal visceral malignancy. The association of skin cancers with other abnormalities is found in nevoid basal cell carcinoma syndrome, Bazex syndrome, Rombo syndrome, xeroderma pigmentosum, dysplastic nevus syndrome, and epidermodysplasia verruciformis. Other genetic syndromes in which benign skin tumors herald the existence of systemic diseases include neurofibromatosis, tuberous sclerosis, Haber's syndrome, and Buschke-Ollendorff syndrome. Diagnosis of one of these syndromes may be ascertained by taking a thorough family history. Recognition of the skin tumor may trigger the proper questions regarding family medical history. Diagnosis hinges upon the physician having a high enough index of suspicion to link the appearance of the skin lesions to the diverse manifestations accompanying these disorders. Recognition will also set the stage for appropriate genetic counseling.