Between September, 1984, and March, 1991, 79 patients underwent heart-lung transplantation for end-stage cystic fibrosis at the Harefield Hospital. Short-term outcome has already been reported, and we now present intermediate-term results. The overall actuarial patient survival was 69% at 1 year, 52% at 2 years, and 49% at 3 years. 17 patients had diabetes mellitus with a survival of 62% to 1 year and 51% to 2 years. 23 patients had one or more other possible high-risk factors, and survival of these patients was 64% at 1 year and 57% at 2 years, compared with 71% and 49%, respectively, in the low-risk group (n = 56). Pseudomonas aeruginosa infection was the most common respiratory infection encountered postoperatively. 92% of patients had at least one episode of acute rejection during the first 3 postoperative months. Lung function was greatly improved after transplantation, the mean forced expiratory volume in 1 s and forced vital capacity increasing from 22% and 35% predicted, respectively, preoperatively to 68% and 70% predicted, respectively, by the sixth postoperative month. This improvement was maintained at 1, 2, and 3 years after transplantation. Lymphoproliferative disorders (4 patients) were successfully treated. Obliterative bronchiolitis developed in 17 patients and the cumulative probability of getting this complication at 1, 2, and 3 years postoperatively was 17%, 23%, and 48%, respectively. Overall, 7 patients were retransplanted. There was no coronary artery disease in the 37 patients who underwent coronary angiography at 1 year, 14 at 2 years, and 9 at 3 years after surgery. 58 patients donated their hearts for subsequent "domino" heart transplantation. Our 5 1/2-year experience with heart-lung transplantation is encouraging but the shortage of donor organs and the complication of obliterative bronchiolitis are the two main obstacles to be overcome.