BACKGROUND: Very little is known about occupational risk factors for chronic rhinosinusitis (CRS). The aim of this study was to evaluate occupational and other potential risk factors for CRS in a Danish population. METHODS: A cross sectional survey study among 4,554 Danes aged 20-75 years evaluated self-reported symptoms of CRS, asthma, and nasal allergy, along with information on smoking habits and occupation. RESULTS: A total of 3,099 returned completed questionnaires (response rate 68.1%). The overall CRS prevalence was 7.8% with no significant differences related to age or gender. Risk ratio estimates revealed an increased risk of CRS among female blue collar workers compared to female white collar workers. Among men the effect of occupation depended on smoking status. Occupational exposure to gasses, fumes, dust, or smoke increased the overall risk of CRS. CRS was reported approximately four times as often in subjects with asthma and in subjects with nasal allergy. Current smoking doubled the CRS prevalence. CONCLUSIONS: CRS prevalence was affected by occupation (blue vs. white collar), but the observed effect depended on gender and smoking status. Exposure to airway irritants (occupational or smoking) increased the CRS prevalence. Studies on larger cohorts are needed to fully assess these tendencies, for example, by more extensive use of Job Exposure Matrix models. Am. J. Ind. Med. © 2012 Wiley Periodicals, Inc.