Biological therapy (biotherapy) performed using biological res-ponse modifiers is sometimes utilized to manage allergic disor-ders. Here, biological agents modifying Th2 type response domi-nant diseases e.g. allergic rhinitis are discussed under the light of current literature. Seventy-88% of asthmatic patients have si-nonasal symptoms and chronic rhinosinusitis patients with nasal polyposis are more likely to develop concomitant asthma. Due to common pathophysiology of allergic asthma and sinonasal di-seases, it is supposed that patients concurrently suffering from both diseases relieve from their symptoms with omalizumab. Like the beneficial effects of omalizumab as add-on treatment in uncontrolled persistent asthma, omalizumab has been shown to improve symptoms and quality of life in patients with ragweed- and birch-induced seasonal and perennial allergic rhinitis. The use of anti-IgE (omalizumab) in asthma management has also some advantages, comprising simultaneous treatment of other IgE-mediated disorders such as allergic rhinitis, an superior sa-fety profile and an easily applicable dosing. Nasal polyp patients have mucosal eosinophilia because of significantly increased le-vels of IgE antibodies and with significantly increased IL-5 tissue expression. High IL-5 level was recently found to be associated with Staphylococcus aureus enterotoxins rather than atopy have provoked researchers to investigate the clinical role of IL-5-blocking strategies. Consequently, mepolizumab and reslizumab have been tried in nasal polyp patients for proof-of-concept stu-dies. The anti-IL-5 monoclonal antibodies reduced nasal polyp scores, but did not considerably improve nasal symptom scores. Due to the important role of IL-4 and IL-13 in the pathogenesis of eosinophilic nasal polyposis, dupilumab was tried as a possible therapeutic agent as well.