Lung transplantation in cystic fibrosis may improve survival for patients with low 5-year predicted survival. Identifying characteristics that affect post-transplantation survival may improve patient selection and survival benefit. Using Cystic Fibrosis Foundation Patient Registry and United Network for Organ Sharing data, we identified 845 lung transplant recipients from 1991-2001, and 12,826 control patients from 1997. We used Cox proportional hazards models to identify variables that influence post-transplantation survival. To estimate the survival benefit of transplantation for patients affected by identified variables, we compared Kaplan-Meier survival curves of transplanted and control patients stratified by 5-year predicted survival. Post-transplantation survival improved annually. Youth, Burkholderia cepacia, and cystic fibrosis-related arthropathy increased the post-transplantation hazard of death. Compared with control subjects, transplanted adults with a 5-year predicted survival of less than 50% without B. cepacia or arthropathy have improved survival. Transplanted adults with B. cepacia, arthropathy, or a 5-year predicted survival of greater than 50% have decreased survival. Transplantation never improves survivorship for pediatric patients. Patients with arthropathy, B. cepacia infection, or younger age derive no aggregate survival benefit and must appraise carefully the high risk of decreased post-transplantation survival. Adult patients with low 5-year predicted survival without B. cepacia infection should receive priority for lung transplantation.