The objective of the present investigation was to study dynamics of the olfactory function in the patients presenting with polypous rhinosinusitis receiving medicamental therapy and in different periods after the surgical intervention. A total of 40 patients were available for the examination in the "Sniffin Sticks" test. The patients of group 1 (n=20) were treated with intramuscular injections of dexamethasone (8 mg twice daily) with gradual tapering the dose during 10 days. The patients comprising group 2 underwent bilateral endoscopic polysinusotomy. Both treatment modalities were followed by momethasone fuorate therapy 6 months in duration. Examination of the patients on the first control visit (i.e. within 1 month after the onset of the treatment) revealed the significant improvement of all measured olfactory parameters that were not significantly different between the two groups. On the second control visit (within 4 months after the onset of the treatment), the patients of group 1 showed a significantly impaired ability to identify smells although other olfactory parameters remained virtually unaltered as compared with those on the first visit. At the same time, no significant impairment of the olfactory function was apparent in the patients of group 2. It is concluded that the patients having non-obstructive polyps in the nasal cavity should be advised in the first place to undergo a course of glucocorticosteroid therapy rather than surgical treatment because the results of conservative therapy and endoscopic polysinusotomy do not differ significantly, at least within the first 4 months after the beginning of the treatment.