Objective. To study the Proetz method mechanism by CFD (computational fluid dynamics) modeling. Material and methods. CFD modeling was performed using a 40-year-old female patient’s CT scans of paranasal sinuses. Modeling is carried out using Mimics Medical 24.0, Ansys Fluent software. Results. When rinsing the nose, the sinuses are filled gradually as liquid sauces are reached after filling the common nasal passage. Fluid removal is effective only from the nasal cavity, the irrigation solution remains in the paranasal sinuses. Conclusion. During the Proetz rinsing method, it is effective for cleaning only the nasal cavity, while the cleaning of paranasal secretions occurs partially, complete aspiration of the irrigation solution from the sinus cavity is impossible.