Over 20 years ago, neurosurgeons were primarily responsible for managing cerebrospinal fl uid (CSF) leaks and meningoencephaloceles that extended into the nasal cavity from the anterior cranial fossa. Typically, skin incisions and craniotomies were required to seal skull base defects from within the intracranial space. Widespread experience with endoscopic sinus surgery techniques and instrumentation has allowed operating on the skull base through the nose with minimally invasive techniques. Skull base procedures, such as transsphenoidal hypophysectomies, are now performed with endoscopic assistance, thereby increasing visualization and obviating the need for operating microscopes. Now, encephaloceles and skull base defects of the sinonasal cavity have been repaired with relatively high success rates using these accepted endoscopic techniques for nearly 20 years . It has truly become the standard of care in routine CSF leaks of the anterior cranial skull base. © Springer-Verlag Berlin Heidelberg 2007.