The overall survival rate for 97 heart transplant recipients operated on from 1968 to 1975 has been 49% at one year and 23% at five years. Progressive improvement in one-year survival has been achieved, from 22% in 1968 to 62% in 1974. The major factors responsible for increasing survival are better understanding and management of acute and chronic rejection. Current results suggest that heart transplantation deserves wider application in the treatment of selected patients with end-stage myocardial insufficiency.