BACKGROUND: Diabetes mellitus (DM) is common in CF and associated with more severe disease. It is unclear whether DM influences outcome of lung transplantation (LTx). METHODS: One hundred twenty-three CF patients evaluated for LTx at our centre were included. Survival was calculated. RESULTS: Patients with and without DM did not differ with regard to gender, age, FEV(1) and BMI prior to LTx. Eighty patients (65%) had a diagnosis of DM before and 13 (11%) only after LTx. Recipients with DM had a significantly higher 1- and 5-year survival (89% and 71%) than those without (71% and 51%). In the multivariate Cox-regression analysis, DM had no impact on LTx-survival. CONCLUSIONS: One- and five-year survival rates after LTx tend to be better in CF recipients with DM compared to those without DM. No impact of DM on the development of BOS was found.