Introduction: Sinus disease in cystic fibrosis (CF) is a known risk factor for disease progression, being the upper airways a primary colonization site of P.aeruginosa. These may function as reservoir for graft colonization after lung transplantation (LTx), increasing risk of rejection. This study examines the burden of sinus disease in CF patients undergoing evaluation for LTx. Methods: A prospective, observational study was performed on consecutive CF patients who attended the MHH outpatient clinics from 11/15 to 01/16 as possible candidates for LTx (NCT 02591524). Data about sinus disease (rhinosinusitis and/or polyposis) and its management were collected. Symptoms were evaluated with the SinoNasal Outcome Test 20 GAV(SNOT20). Upper airway colonization was assessed by microbiological culture of nasal lavage (NL). Results: 28 patients were enrolled, 3 refused to participate. Median age was 33(24-40) years. Sinus disease was reported in 14(50%) pts, of whom 13(46%) had undergone sinus surgery. No pt was receiving topical nasal antibiotics at inclusion. NL microbiology is depicted in figure 1. Median SNOT20 was higher in those who underwent surgery [42(20-51) vs. 20(12-30),p=0.04]. Conclusion: At least a half of the patients evaluated for LTx presented signs and/or symptoms of sinonasal disease; early identification of these patients is crucial to recommend appropriate treatment targeting eradication and hopefully improve lung transplantation outcomes.