A nasal polyp is an oedematous thickening of a mucous membrane that forms a suspension process in the broad or narrow stalk. It is usually localized in the upper part of the nose and around the opening of the paranasal sinuses with the expansion in the nasal cavity. In the case of a larger number of polyps we are talking about polyposis which is characterized by an impaired function of the nose. Nasal polyposis is a part of an inflammatory reaction that affects the mucous membrane of the nose, paranasal sinuses and often the lower respiratory tract. These are the most common benign tumors of the nose and they are found in 1 to 4 % of the total population. There is an increasing incidence of chronic inflammatory diseases of the airway, especially asthma which the nasal polyps are often associated with, and so the incidence of nasal polyposis is increasing, too. The conservative treatment of nasal polyps is focused on the local or systematic use of medication from the group of steroids. Today, it is considered that this kind of treatment has an advantage compared to a surgical treatment. Another form of treatment is a functional endoscopic sinus surgery and in practice it has replaced the radical clinical surgery. A combined treatment involves application of steroids prior to surgery and after surgery in order to reduce the recurrence of the disease.