The subject of developed theme is xenotransplantation as future alternative to allotransplantation. because of its an experimental nature and being unrecognized as therapy method, xenotransplantation causes ethical and legal problems, which must be solved before the clinical trials start. Variuos sources of information and reports of councils on bioethics are used to examine the ethical issues raised by xenotransplantation. The other part of work is based on overlooking and analysis of World health organization, council of Europe and European Union laws concerning xenotransplantation, which help to reveal the legal problems. The situation in Lithuania is presented.