The limiting factor in organ transplantation is the availability of organs. Continuing work to improve the public's willingness to donate organs and inspire hospital staff to collaborate in organ procurement is essential. Identification of patients who will not benefit from transplantation can also increase the availability of organs. Grafts may also be saved by identification and appropriate treatment of recurrent renal disease. Xenotransplantation may eventually solve the problem, but major obstacles remain. Meanwhile, work in this field may help to clarify mechanisms of rejection. New immunosuppressive drugs may improve graft survival and reduce the incidence and progression of chronic rejection.