This chapter discusses anatomy of the nose, paranasal sinuses, and anterior skull base, where the nasal cavity and paranasal sinuses are paired airspaces within a bony and cartilaginous frame work. The mucosal lining is composed of ciliated, pseudostratified columnar epithelium with interspersed goblet cells, nonciliated columnar cells, and basal cells. The blood supply to the nasal septum and paranasal sinuses is extensive and comes from branches of both the internal and external carotid arteries. The bony scroll of the turbinates is covered by fibrovascular erectile submucosal tissue and respiratory epithelium. Inferior turbinate provides the most significant amount of temperature regulation, humidification, and filtration of inspired air. The suprasellar area harbors the circle of Willis. The mucociliary function of the maxillary sinus physiologically clears secretions to the natural ostia and infundibulum. The infundibulum is a three-dimensional space that serves as the physiological clearance area of the anterior ethmoid, maxillary and frontal sinuses.