The case histories of six cystic fibrosis patients awaiting heart-lung transplantation are reviewed. They all deteriorated with severe hypoxia and hypercapnia before donor organs became available. Nasal intermittent positive pressure ventilation was used in preference to conventional ventilation with excellent results in four patients. There were no episodes of hypotension or toxaemia and the patients were in a stable condition at the time of surgery and made an excellent post-operative recovery. The patients who were transplanted and the patient who died, for whom suitable donor organs did not become available, probably had a more comfortable time than they would have done if treated with conventional ventilation. This method of ventilation appears to be a useful bridge to transplantation when a patient suddenly deteriorates. It gives them a chance of survival for a few more days or even weeks during which time an urgent search for donor organs can be made. This is also a very cost effective method of ventilation and does not encroach on conventional Intensive Care Unit (ICU) facilities.