Objective: Many studies have assessed clinical and functional aspects of lower airway affections in cystic fibrosis. Conversely, few studies have been performed to assess the clinical and functional affections of upper airways. The objective of the present study was to correlate the variables obtained by nasal and paranasal sinuses endoscopy, paranasal sinus laboratory and computed tomography (CT) scan findings, and to check the association with severity and genotype of cystic fibrosis patients. Methods: Clinical and laboratory study of 50 patients with cystic fibrosis at a university center. All patients were submitted to CT scan, nasal and paranasal endoscopy and bacterioscopy of maxillary sinus, trachea and oropharynx secretion. Severity of cystic fibrosis was assessed by Shwachman score and the most frequent genetic mutations were identified. Results: The prevalence of polyposis in the studied population was 36% and it was greater among homozygote for Delta F 508. Shwachman score was correlated with age (p = 0.003). The genotype was correlated with presence of nasal polyposis (p = 0.006). There was no association between affections in CT scan and severity of cystic fibrosis (CF). Patients presented high prevalence of early colonization of Pseudomonas aeruginosa. Conclusions: Sinus disease in CF patients presents several clinical, endoscopic and tomographic affections. Although most of them are not correlated with severity and disease genotype, severity of CF is correlated with age and presence of polyposis is genotype-dependent. (C) 2006 Elsevier Iretand Ltd. All rights reserved.7114150