The application of gene transfer technologies to the field of solid organ transplantation is uniquely appealing due to open access to the donor organ at the time of removal and the need for a local biological effect limited to the allograft. The objectives of gene transfer technology in the field of experimental heart transplantation include: firstly, modification of allograft phenotype and secondly, modulation of the host alloimmune response. Both objectives can theoretically decrease or eliminate the need for lifelong immunosuppression with its attendant risks. This article will review the principles and current methodology of gene transfer technology, applications of gene transfer technology to allo- and xeno- transplantation and the current status of clinical trials on gene therapy.