Acute inflammation of the mucous membrane of the nose and paranasal sinuses (acute rhinosinusitis (ARS)) is a fairly common pathology in pediatrics and otorhinolaryngology. The aim of the research was to improve the effectiveness of treatment children with ARS by introducing a combination complex of natural plant extracts "Sinudafen" and effervescent isotonic seawater solution "Sparklin" and to investigate the effect of the proposed complex treatment on the frequency of repeated ARS. Materials and methods. The study was conducted between February and December 2023 in two independent centers. The study included 98 patients with signs of ARS. The Main group - 67 patients who received "Sinudafen" and "Sparklin" for 10-14 days, symptomatic and/or etiotropic therapy if necessary. The Control group - 31 patients who received standard therapy. The results. The examination carried out on the 14th day showed that, compared to standard treatment, the patients of the Main group had a statistically significantly lower risk of maintaining such local symptoms of ARS (edema of the mucous membrane and mucous secretions from the nose). With the faster rates of recovery of children in the Main group, the pharmacological load on patients decreased significantly. The use of "Sinudafen" and "Sparklin" in comparison reduced the need to prescribe antibacterial and antiseptic drugs in the acute period. Better clinical dynamics was accompanied by a reduction in the length of hospitalization, the use of "Sinudafen" + "Sparklin" increased the chances of reducing the duration of the acute period within ≤4 days. Conclusions. The use of "Sinudafen" and "Sparklin" complex in the treatment of children with ARS allows for a 3.8-fold increase in the chances of recovery within ≤4 days. The proposed complex treatment reduces the need for antibiotics/anesthetics by 15.8 times and reduces the risk of repeated episodes of ARS by 18.2 times during the 6-month follow-up period. The use of "Sinudafen" with "Sparklin" is characterized by good tolerability, absence of side effects, high adherence, and also reduces the cost of treatment of one episode of ARS by 50%. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.