There were 24 patients with chronic adenoiditis in the 1st group, another 24 patients with chronic adenoiditis in association with otitis media effusion (OME) were included in the 2d group. The study of mucosal immunity included assessment of SIgA, IL-6, IFN- and IL-10 levels in nasal washes. Decrease of SIgA content and increase of the number of IFN-γ-positive samples was revealed in children from the 2nd clinical group, which allows to regard these characteristics of the mucosal immunity as the risk factors for the development of otitis media with effusion.