This paper reports results of the study of nasal mucosal microflora in patients with chronic sinusitis (CS) and rhinitis (CR). The study revealed dysbacteriosis of nasal mucosa in the patients of both groups. At the same time, the structure of mucosal microbiocenoses was not significantly different in patients with CS and CR. Moreover, the study has demonstrated enhanced pathogenic activity of Staphylococcus bacteria in both CS and CR.