At Stanford University Medical Center from January 1968 until January 1984, 288 patients received 313 heart transplants. The immunosuppressive regimen before December 1980 consisted of azathioprine and prednisone, with or without rabbit antithymocyte globulin. After that time cyclosporine replaced azathioprine. In 92 recipients of 95 heart allografts, the 1- and 3-year survival rates were 82% and 65% to 70% respectively. In the 3 years from March 1981 to March 1984, successful heart-lung transplantation was accomplished in 13 of 19 recipients, using cyclosporine-based immunosuppression. Survival ranged from 1 to 38 months. While it is true that cyclosporine has improved survival in heart transplant recipients, has allowed successful heart-lung transplantation to be performed, has shortened intensive care unit and total hospital stays and therefore hospital costs, and has allowed easier management of rejection and infection, several disconcerting problems have not yet been resolved. These include hypertension that is difficult to control and renal dysfunction in all patients, and the fact that cellular and humoral rejection still occurs, as manifested by graft atherosclerosis, bronchiolitis obliterans and classic acute rejection. Better understanding and application of cyclosporine immunosuppression will undoubtedly minimize both cyclosporine- and non-cyclosporine-related postoperative complications and will improve survival even further.