It is generally recognized that the microflora has an impact on the course of chronic rhinosinusitis with nasal polyps. However, it is not quite clear which bacteria play a key role and how they affect eosinophilic inflammation. Sixty-nine patients with chronic rhinosinusitis and nasal polyps were examined. It was found that bacterial inoculation from the nasal cavity in this disease was significantly higher than that in healthy people, mainly due to staphylococci (2,131,001 (range 1,600,000—4,520,002) and 10,000 (range 300—11, 000) CFU/ml). Identification of staphylococcal species showed that most of them were represented by Staphylococcus aureus (500,000 (range 400,000—3,500,000) CFU/ml) and Staphylococcus epidermidis (500,000 (range 120,000—1,000,000) CFU/ml). Moreover, the greater was the concentration of Staphylococcus aureus, the lower was the level of immunoglobulin E. The findings suggest that it is necessary to use antimicrobials in the treatment of patients with rhinosinusitis and nasal polyps.