A description of different members of the same family affected by Cowden disease gives us the opportunity of a detailed review of the literature concerning the phenotypic and genotypic characteristics of this disease. Muco-cutaneous, mammary, thyroid, intestinal, urogenital, bone and neuro-sensorial involvement are detailed as well as pattern of inheritance and the inter and intra familial variability of expressivity. The different attempts to identify the implicated gene(s) are presented but they have failed at the present time.