A connection between allergic rhinitis (AR) and chronic rhinosinusitis (CRS) and specifically CRS with nasal polyposis (CRSwNP) has long been hypothesized. Clinical studies, however, have generally been unable to support this. The use of broad phenotypic categories likely obscures the association. In certain subtypes of CRS such as allergic fungal rhinosinusitis (AFRS) and central compartment atopic disease (CCAD), aeroallergen sensitivity is very common. Allergy-mediated inflammation likely drives these, and possibly other, subtypes of CRS. The hallmarks of management include relief of sinonasal obstruction with endoscopic sinus surgery and management of inflammation with immunotherapy and topical and/or systemic therapies.