BACKGROUND: Intensive care unit (ICU) admission of adults with cystic fibrosis (CF) is controversial because of poor outcome. This appraisal needs re-evaluation following recent changes in both CF management and ICU daily practice. Objectives were to determine long-term outcome of adults with CF admitted in ICU and to identify prognostic factors. METHODS: Retrospective multicenter study of 60 ICU hospitalizations for 42 adult CF patients admitted between 2000 and 2003. Reason for ICU admission, ventilatory support provided and one-year survival were recorded. Multiple logistic analysis was used to determine predictors of mortality. RESULTS: Prior to ICU admission, all patients (mean age 28.1 +/- 8 yr) had a severe lung disease (mean FEV1 28 +/- 12% predicted; mean PaCO2 47 +/- 9 mmHg). Main reason for ICU hospitalization was pulmonary infective exacerbation (40/60). At admission, noninvasive ventilation was used in 57% of cases and was successful in 67% of patients. Endotracheal intubation was implemented in 19 episodes. Overall ICU mortality rate was 14%. One year after ICU discharge, 10 of the 28 survivors have been lung transplanted. Among recognized markers of CF disease severity, only the annual FEV1 loss was associated with a poor outcome (HR = 1.47 [1.18-1.85], p = 0.001). SAPSII (HR = 1.08 [1.03-1.12], p < 0.001) and endotracheal intubation (HR = 16.60 [4.35-63.34], p < 0.001) were identified as strong independent predictors of mortality. CONCLUSION: Despite advanced lung disease, adult patients with CF admitted in ICU have high survival rate. Endotracheal intubation is associated with a poor prognosis and should be used as the last alternative. Although efforts have to be made in selecting patients with CF likely to benefit from ICU resources, ICU admission of these patients should be considered.