The first liver transplantation carried out in Spain for the treatment of type I familial amyloidotic polyneuropathy (FAP I) is presented. The reason for the operation was based on the liver being responsible for the synthesis of abnormal transtirretin (TTR) constituting the peculiar amyloid of the disease. Following transplantation a rapid and noticeable decrease in abnormal TTR was observed and the evolution of the clinical picture after 18 months of surgery is favorable with progressive improvement of the neurologic symptoms and normal function of the graft. These encouraging results coincide with those of the Swedish group of Umea, the pioneer of this procedure.