Chronic rhinosinusitis is a common complex medical condition associated with high therapy costs and quality of life impairment. The European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2012 delineates the current standard of management of the patient with chronic rhinosinusitis for both defined disease forms: with and without polyps. Medical history and endoscopic or CT findings are needed for the correct diagnosis. Therapy of chronic rhinosinusitis aims at achieving a local disease control and reducing patients' symptoms. The center point of conservative therapy of both forms is the topical application of steroids together with nasal saline irrigations. In case of persistence of symptoms or in severe chronic rhinosinusitis with polyps, different local application methods of steroids or short systemic steroid cures should be considered. In case of insufficient disease control with conservative treatment, functional endoscopic sinus surgery is the accepted as “gold standard”. Purpose of the surgical management is opening of the sinus ostia in order to improve sinus ventilation and mucociliary clearance as well as to facilitate a wide distribution of topical drugs. Due to technical advances, endoscopic sinus has been reported to be a safe and effective procedure.