Long-term results of organ transplant survival have been hampered by the process of chronic rejection and the side effects of current immunosuppression. The development of gene transfer techniques has kindled expectations to overcome such complications through tolerance induction with intrathymic donor cDNA injection or bone marrow engineering and the delivery of molecules with immunomodulating activity to the transplanted organs. Efforts to discover vectors that effectively and safely transfect tissues, together with the search of the proper “antirejection” gene, will occupy scientists for a while before gene therapy may be applied to transplantation.