Endoscopic sinus surgery, is a surgical technique used in the treatment of sinus diseases. Surgery is the process of cleaning the inflamed tissues and / or polyps in the sinuses with endoscopes and auxiliary instruments from the nose without making an external incision. While intervening in the sinuses, the sinus channels that will provide healthy ventilation of the sinuses are also opened. With endoscopic sinus surgery, septal deviations and turbinate pathologies, if any, can also be corrected. Functional endoscopic sinus surgery is preferred in chronic sinusitis with or without polyps that do not pass with drug treatment for more than 3 months. When deciding on surgery, sinus tomography should be used to determine the severity of the disease and concomitant pathologies of the spetum or turbinate. Although the duration of the operation varies depending on the severity of the disease, it takes an average of 1.5-2 hours. It is a surgery performed under general anesthesia. An average of 10 days of rest is sufficient after surgery.