For the beginner or for the accomplished sinus surgeon, mastering the anatomy of the lateral nasal wall is an ongoing challenge. Even though there are excellent standard anatomical references and equally outstanding sinus courses with cadaver dissection, a reference depicting the surgical anatomy is needed. A step-by-step surgical approach on the anterior nasal spine to the anterior wall of the sphenoid is presented. The sinus surgeon is confronted with a wide range of different spaces created by the ethmoid bone. No other bone in the human body has so many anatomical variations. Four...