Multiple hamartoma syndrome, also known as Cowden's disease, is a rare genodermatosis with multiple organ system involvement affecting tissues derived from ectodermal, endodermal, and mesodermal tissue layers. We describe two previously unreported cases of multiple hamartoma syndrome in a father and daughter. Both show classic features of multiple hamartoma syndrome, as well as other mucocutaneous findings. The father has been shown to have substantial cutaneous deposits of amyloid in the absence of underlying plasma cell dyscrasia or malignancy. Both individuals have undergone excision of a unique fibroma that has features that have been reported only in multiple hamartoma syndrome and should be added to the criteria used to define the entity.