When successful solid organ transplantation was initiated almost 40 years ago, its current success rate was not anticipated. But continuous efforts were undertaken to overcome the two major obstacles to success: injury caused by interrupting nutrient supply to the organ and rejection of the implanted organ by normal host defense mechanisms. Solutions have resulted from technologic medical advances, but also from using organs from different sources. Each potential solution has raised ethical concerns and has variably resulted in societal acclaim, censure, and apathy. Transplant surgery is now well accepted, and the list of transplant candidates has grown far quicker than the availability of organs. More than 30,000 patients were awaiting organs for transplantation at the end of March 1993. While most organs came from donors declared dead by brain criteria, the increasing shortage of donated organs has prompted a reexamination of prior restrictions of donor groups. Recently, organ procurement from donors with cardiac death has been reintroduced in the United States. This practice has been mostly abandoned by the U.S. and some, though not all, other countries. Transplantation has been more successful using organs procured from heart-beating, "brain dead" cadavers than organs from non-heart-beating cadavers. However, recent advances have led to success rates with organs from non-heart-beating donors that may portend large increases in organ donation and procurement from this source.