Background: Lung transplantation (LTx) is a therapy for patients with cystic fibrosis (CF) end-stage lung disease. Pseudomonal airway colonization (PAC) is common in CF. Objectives: We investigated the influence of post-transplant sinus surgery and daily nasal douching on PAC after LTx and the influence of PAC on survival and bronchiolitis obliterans syndrome (BOS). Methods: CF patients transplanted at our centre were included (November 1992 to December 2009). Clinical data, including microbiological data before and after LTx were collected. Survival and BOS following LTx were compared for CF recipients with and without PAC by Kaplan-Meier statistics and Cox regression analysis. Results: Ninety-four CF patients were transplanted, of whom 82 (87%) underwent sinus surgery after transplantation, and 65% of 66 patients with pre-transplant PAC had persistent PAC after transplantation. Upper and lower PAC is related. Patients without PAC after transplantation had a significantly better survival rate, and BOS was less frequent with a later onset. PAC was the only significant parameter for the development of BOS stage 2 in the multivariate analysis for cytomegalovirus infection, acute rejection and PAC. Conclusions: Sinus surgery and daily nasal douching reduced PAC in LTx recipients. Absence of post-transplant PAC had a positive impact on post-transplant survival and the development of BOS.