['Chronic rhinosinusitis has many risk factors; however, the effect of anti-tumour necrosis factor therapy has not been investigated in depth. Our experience points to a detrimental clinical effect in overall prevalence of chronic rhinosinusitis, despite its benefit in certain subtypes.', 'A telephone survey was performed to parallel the findings of the Global Allergy and Asthma European Network chronic rhinosinusitis screening survey. This was itself based on the widely recognised European Position Paper on Rhinosinusitis and Nasal Polyps criteria.', 'A total of 120 patients responded to the survey. The prevalence of chronic rhinosinusitis in the anti-tumour necrosis factor therapy population was 20 per cent (95 per cent confidence interval = 12.84-27.16). When compared using a chi-square test, for a two-by-two contingency table, this finding was significant against the prevalence recorded in the normal population.'] Is anti-tumour necrosis factor therapy associated with certain subtypes of chronic rhinosinusitis?