Endoscopic third ventriculostomy is the most widely performed neuroendoscopic procedure around the world. Several scientific papers appear in the scientific literature every month, with an increasing number, given the great interest neuroendoscopy has aroused as well as controversies about certain aspects of endoscopic third ventriculostomy. With this reasoning, the goal of this book is to be a reference in the revision of classic concepts and scientifically proven aspects about the indications and techniques of endoscopic third ventriculostomy, as well as new neuroendoscopic tendencies. The book is structured in 2 parts and into 7 chapters. Part I   Classic Concepts   comprises the first 2 chapters, covering general aspects of neuroendoscopy such as historical notes, endoscopic anatomy and ventricular system physiology. Part II   State-of-the-Art   comprises chapters 3 to 7.