This issue of Immunology and Allergy Clinics, guest edited by Sandra Y. Lin, MD, will provide up-to-date clinical concepts regarding the diagnosis and management of the patient with Rhinosinusitis. Articles in this outstanding issue include: Current Concepts in the Management of Allergic Fungal Sinusitis; Aspirin Desensitization for Nasal Polyps in Aspirin-exacerbated respiratory disease (AERD); Primary Immunodeficiency and Rhinosinusitis; How to Measure Success in the Treatment of Patients with Chronic Rhinosinusitis; What is the Role of Macrolides and Doxycyline in Chronic Rhinosinusitis?; The Role of Biologics in the Treatment of Nasal Polyps; Personalized Medicine in Chronic Rhinosinusitis: Endotypes, Phenotypes, and Biomarkers; Management of Sinusitis in the Cystic Fibrosis Patient; The Microbiome and Chronic Rhinosinusitis; The Role of Allergic Rhinitis in Rhinosinusitis; The Role of Air Pollution in Chronic Rhinosinusitis; Odontogenic Sinusitis: Current Concepts in Diagnosis and Treatment; Olfactory Dysfunction and Chronic Rhinosinusitis; and The Impact of Allergen Immunotherapy on Chronic Rhinosinusitis.