This article defines chronic rhinosinusitis (CRS) and shares contemporary principles for its diagnosis and management, focusing on practical considerations for rhinoplasty surgeons. Nasal obstruction, the most common symptom of CRS, is frequently the chief complaint of patients seeking functional rhinoplasty surgery. Because correcting sites of anatomic obstruction to nasal airflow alone is unlikely to adequately treat CRS, rhinoplasty surgeons must have a firm understanding of the origin, diagnosis, and management of this disease process. With no single cause identified, CRS is likely an umbrella diagnosis or syndrome encompassing numerous causative factors, with the common end point of chronic sinonasal inflammation.