Combined heart-lung transplantation is an effective means of treating end-stage right ventricular failure in selected patients. Perioperative mortality is less than 30 percent, and may be further reduced by more-rigorous patient selection. About one-third of the patients can be expected to have good and lasting results, with a return to a fully active and normal life. Life expectancy is not known inasmuch as the longest follow up so far is four-and-a-half years. There are, however, three areas of serious concern: (1) The risk of developing progressive airway damage (obliterative bronchiolitis and bronchiectasis) is high. It occurs in about one-half of the patients surviving surgery and may occur as late as two years after the operation. The pathogenesis of this process is not yet understood, but it may be reversible if detected very early and treated aggressively with corticosteroids; otherwise, it follows a course of steady deterioration. (2) Cyclosporine as a maintenance immunosuppressive drug leads to progressive and irreversible renal impairment. Alternative means of long-term immunosuppression will need to be developed in the future. (3) Graft intimal proliferation affecting both the coronary and the pulmonary vessels may eventually limit graft survival.