['There is an increasing knowledge that the severity of perennial allergic rhinitis is associated with nasal carriage of Staphylococcus aureus (S. aureus). The aim of this study was to evaluate the rate of bacterial colonization with S. aureus in the nose of subjects with and without chronic rhinosinusitis (CRS) and to correlate these findings with the severity of symptoms and the extent of the disease.', 'Open, prospective controlled trial.', "190 subjects with CRS and 42 subjects with septal deviation without sinusitis (control subjects) were included in this study. Swabs were taken endoscopically from the middle meatus and bacteria were cultured and identified. Airway symptoms were assessed by subjects in standardized questionnaires and frequencies of respiratory tract infections were noted. The rhinosinusitis extent was graded by CT scan assessment. Analysis of variance, chi-square test, and Pearson's correlation test were applied for statistical analyses.", 'The S. aureus carriage rate was 25.5% in CRS and 31.4% in control subjects. Further facultative pathogens were cultured in 20.6% of subjects with CRS and in 8.5% of controls. 73.8% of S. aureus were ampicillin-resistant, multiresistant strains were cultured in 5.8%. Most airway symptoms and the frequencies of respiratory tract infections were significantly higher in the CRS group compared with control subjects. In post hoc comparison between the subgroups with and without S. aureus colonization, no significant differences were found between the extent of rhinosinusitis and the severity of airway symptoms.'] Is nasal colonization with Staphylococcus aureus associated with the severity of symptoms or the extent of the disease in chronic rhinosinusitis?