The impetus to consider xenotransplantation as a viable treatment option in the future remains clearly grounded in the possibility that, even were less controversial sources of organ transplantation to be maximized, there would still remain a shortage of organs for transplantation. On the plus side, xenotransplantation has a number of immediate attractions; not least that, were it possible to breed sufficient numbers of transgenic animals, and were we able to overcome immunological and physiological problems, it would provide a ready supply of organs, permit the planning of surgery and perhaps reduce the need for expensive immunosuppressive regimes. Equally, the development of cellular xenografting is potentially of benefit in respect of certain degenerative conditions, such as Parkinson’s disease. However, the promise of xenotransplantation, even if established, would not be without costs, both ethical and legal.