Between September 1984 and October 1988, 27 patients underwent combined heart-lung transplantation for treatment of end-stage respiratory disease caused by cystic fibrosis. The actuarial patient survival was 78% at 1 year and 72% at 2 years. Bacterial respiratory infections were common in the early postoperative period and necessitated vigorous medical therapy. The dose of cyclosporine required in these patients was higher than in conventional transplant recipients, and this contributed to an increased cost of postoperative care. Lung function was greatly improved after transplantation, and long-term survivors achieved an excellent quality of life. Lymphoproliferative disorders developed in two patients; these disorders regressed after a reduction in immunosuppression. Two patients required retransplantation: one because of obliterative bronchiolitis and the other because of recurrent respiratory infections associated with a moderate tracheal stenosis and severe deterioration in lung function. A modification of the technique used for heart-lung transplantation allowed 20 hearts from cystic fibrosis patients to be used for subsequent heart transplantation. Immediate heart function was satisfactory in all cases. The actuarial survival of the recipients of these domino heart transplants was 75% at 1 year. No coronary artery disease was present in the 12 patients who have undergone coronary angiography at 1 year.