Results of the study on adaptive immunity in patients with polypous rhinosinusitis (PRS) proved to depend on the degree of eosinophilia in the peripheral blood. The patients were allocated to two groups, one comprised of those having up to 150 eosinophils per 1 microliter the other of the patients with a higher eosinophil concentration. Patients of the former group had a significantly reduced number of CD3+, CD4+, CD8+, and CD20+cells in the peripheral blood that may indicate the necessity of administering immunotropic agents. The opposite picture is characteristic of the latter group in which a rise in the number of the above cells is associated with the increased amount of IgG- and IgA-positive cells. In this situation, the use of systemic immunotropic agents should be restricted. It is concluded that evaluation of systemic and local adaptive immunity is of importance for the choice of an adequate strategy for the treatment of patients with polypous rhinosinusitis.