This book highlights the endoscope as an instrument that can be used through natural openings in the nose (endonasal), as well as secondarily exposed corridors (transorbital, transoral) for minimal access approaches to the skull base. The text is divided into six sections reflecting the general concepts of skull base surgery, management of common skull base lesions, and the major corridors for approaching the skull base in a minimally invasive manner: transorbital, transnasal, and transoral. At the beginning of each section, relevant surgical anatomy is described. We have also included a chapter on minimal access treatment of superior canal dehiscence, which is of particular interest to neurotologists.