Fungal flora is one of the causes of inflammatory, including polypous, processes in the nasal cavity. In this regard, studies aimed at reducing the effect of fungal sensitization (FS) on the course of chronic polypous rhinosinusitis (CPRS) are relevant. The objective of the study was to evaluate the effect of various treatment options on the clinical course of the disease in patients with chronic polypous rhinosinusitis against the background of sensitization to fungi. The study included 90 patients with chronic polypous rhinosinusitis in combination with FS. The patients were divided into two groups – the first clinical group (G1) and the second clinical group (G2). G1 patients received allergen-specific immunotherapy (ASIT) according to the scheme. G2 patients received basic treatment. Evaluation of the clinical efficiency of ASIT was made based on complaints, assessment of symptom severity on a visual analog scale (VAS), and rhinoendoscopic examination. The treatment outcomes were evaluated on a 4-point scale, with excellent results (4 points) – complete remission of the disease during the follow-up period (6–12 months); good (3 points) – exacerbation of the disease 1-2 times a year, in mild form and removed by expectant treatment; satisfactory (2 points) – the number of exacerbations did not decrease. The use of ASIT therapy is pathogenetically justified and leads to a significant improvement in the clinical condition of patients with CPRS with FS.