Background. Lung transplantation for patients on ventilators is a controversial use of scarce donor lungs. We have performed 500 lung transplants in 12 years and 21 of these have been in ventilator-dependent patients. Methods. A retrospective review of patient records and computerized database was performed. Living patients were contacted to confirm their health and functional status. Results. Patients included 13 men and 8 women with a mean age of 43 years. Sixteen patients were considered stable awaiting lung transplant, whereas 5 patients were unstable with acute graft failure after prior lung transplantation. Stable patients had been ventilated for a mean of 57 ± 46 days whereas unstable patients had been supported for 10 ± 9 days. Half of the patients required cardiopulmonary bypass support during the transplant, and there was no statistical difference in the frequency of CPB in stable and unstable patients (p = 0.61). Three hospital deaths included 0 of 16 of the stable patients and 3 of 5 of the unstable patients (p = 0.01). Long-term actuarial survival was significantly better in stable versus unstable patients (p = 0.02), with 5-year survival 40% for stable patients and 0% for unstable patients. Conclusions. Lung transplantation can be successfully conducted in stable patients who have become ventilator dependent after listing for transplantation. Acute retransplantation for early lung dysfunction is high risk and has produced poor long-term results. (C) 2000 by The Society of Thoracic Surgeons.