INTRODUCTION: The role played by Mycoplasma pneumoniae and Chlamydophila pneumoniae in the pathogenesis of chronic rhinosinusitis with nasal polyps has been the object of ongoing debate. We used real-time polymerase chain reaction to investigate the prevalence of both microorganisms in the nasal tissue samples of patients and controls.METHODS: We extracted DNA from nasal polyp samples obtained during functional endoscopic sinus surgery and the inferior turbinate samples of controls undergoing septoplasty. We used the highly sensitive real-time polymerase chain reaction to detect the presence of M pneumoniae and C pneumoniae DNA.RESULTS: Patients with chronic rhinosinusitis with nasal polyps consisted of 62 individuals (39 men; mean age 51 years); the control group consisted of 24 individuals (13 men; mean age 45 years). All samples from both groups were negative for M pneumoniae and C pneumoniae DNA.CONCLUSION: We have demonstrated that the likelihood of M pneumoniae and C pneumoniae acting as an ongoing inflammatory stimulus in chronic rhinosinusitis with nasal polyps is slim.