The best way to prevent complications from cerebrospinal fluid rhinorrhea (CSF) is efficient diagnosis and quick endoscopic repair. Endoscopic endonasal approaches are efficacious and with decreased morbidity. In this course, presentation to the otolaryngologist’s office, causes of CSF leaks as well as controversial aspects of evaluation and diagnosis will be discussed. Case studies of CSF rhinorrhea involving the frontal, ethmoid/cribriform and the sphenoid sinuses are presented and discussed. Surgical videos are shown demonstrating repair techniques for each individual location involved. Post-operative management will be discussed. This course will not discuss skull base reconstruction after ablative surgery for tumors.