Topicality: Chronic inflammatory diseases of the tonsils occupy a significant place in the structure of otorhinolaryngological pathology. The transition of inflammation to a chronic form is associated with the suppression of factors of colonization resistance of this biotope, the emergence of pathogenic microorganisms such as St. рyogenes and S. aureus. Аgainst the background of developing dysbiosis and immune imbalance, a number of complications from organs and systems may develop. Therefore, the search for means for effective topical etiotropic treatment of chronic tonsillitis and, at the same time, gentle on the indigenous microflora, is relevant. Materials and methods: The study involved 52 patients with chronic tonsillitis. All patients were divided into 2 groups of 26 each. Subjects of the 1st group in local therapy used the bacterial component "Bioplasmix throat spray", and patients in the 2nd group – used the traditional course of treatment: washing the lacunae of the tonsils with antiseptic agent – decamethoxine at a concentration of 0.2 mg/ml. Results and discussion: Studies have shown the selective antimicrobial activity of "Bioplasmix Throat Spray". Thus, in relation to the main pathogens "Bioplasmix Throat Spray" showed a pronounced antibacterial effect and, at the same time, helped to normalize the population level of indigenous microflora, which indicates the restoration of colonization resistance of the biotope. The positive dynamics of the main complaints of patients and pharyngoscopic signs testified to the clinical effectiveness of "Bioplasmiх Throat Spray". The analysis of clinical indicators in patients of the 2nd group showed a decrease in the severity of patient complaints and objective signs of the disease during treatment with decamethoxine. The results of repeated microbiological studies showed that, unlike "Bioplasmiх Throat Spray", the broad spectrum of antimicrobial action of decamethoxine does not contribute to the restoration and maintenance of high population levels of indigenous microflora of thepalatine tonsils.