Hereditary factors in cancer in humans recently have been receiving increasing attention. In spite of significant advances in understanding the genetic factors important in the etiology of many cancers and cancer‐predisposing diseases, surprisingly little interest has been given to application of this knowledge to cancer control. Because of ease in observation of lesions and in biopsy confirmation of disease, the cutaneous system lends itself well to investigation and application of genetic information for cancer control. Many hereditary cancers involve the skin either directly, or indirectly, through the presence of distinguishing dermal lesions which may be precursors or concomitant with cancers of other anatomic sites. All presently known dermatologic conditions associated with cancer which have a definite or presumptive hereditary etiology are reviewed and arranged according to specific mode of inheritance. Such information could be beneficial to the physician. All relatives of his patients with a known hereditary cancer or hereditary disorder predisposing to cancer or associated with cancer should be urged to have an early medical examination.