Chronic rhinosinusitis is an inflammatory disease of the paranasal sinuses that occurs in 1% to 5% of the U.S.It may significantly decrease quality of life. Chronic rhinosinusitis is defined by the presence of at least two out of four cardinal symptoms (i.e., facial pain/pressure, hyposmia/anosmia, nasal drainage, and nasal obstruction) for at least 12 consecutive weeks, in addition to objective evidence. Objective evidence of chronic rhinosinusitis may be obtained on physical examination (anterior rhinoscopy, endoscopy) or radiography, preferably from sinus computed tomography. Treatment is directed at enhancing mucociliary clearance, improving sinus drainage/outflow, eradicating local infection and inflammation, and improving access for topical medications. First-line treatment is nasal saline irrigation and intranasal corticosteroid sprays. There may be a role for antibiotics in patients with evidence of an active, superimposed acute sinus infection. If medical management fails, endoscopic sinus surgery may be effective. Patients not responding to first-line medical therapy should be referred to an otolaryngologist, and selected patients with a history suggestive of other comorbidities (e.g., vasculitides, granulomatous diseases, cystic fibrosis, immunodeficiency) may also benefit from referral to an allergist or pulmonologist.