Forty five patients with cystic fibrosis (age 5-15 years) were assessed for heart-lung transplantation between September 1987 and March 1990. The two main conditions for acceptance were (i) life expectancy less than 2 years and (ii) a severely impaired quality of life. Patients were accepted onto an active waiting list (n = 26), a provisional waiting list (n = 15), or not accepted (n = 4). Selection was made on clinical grounds with objective measurements used as an aid in assessment. As expected, the mean values for objective measures were significantly different between patients on the active waiting list compared with the provisional waiting list/not accepted group for resting heart rate (118/minute v 101/minute), percentage of ideal weight (83.2% v 93.1%), forced expiratory volume at one second as percent of predicted normal (27.3% v 47.6%), Shwachman-Kulczycki score (33.6 v 52.5), Chrispin-Norman x ray score (25.8 v 22.1), 12 minute walk (540 m v 854 m), and minimal oxygen saturation (81.5% v 92%). Psychological evaluation demonstrated a 55% incidence of individual and a 50% incidence of family morbidity. Of the 26 patients accepted onto the active waiting list, 11 have been transplanted (mean waiting time 3.3 months), 10 have died within a mean of 3.7 months of acceptance, and five remain on the active list (mean 5.6 months).