CSF rhinorrhea is defined as abnormal leakage of cerebrospinal fluid through the nasal cavity after the break in the barriers separating the nasal cavity from the subarachnoid space. CSF rhinorrhea is an important clinical entity as it can lead to serious complication and in some cases mortality. The prompt clinical diagnosis is important, any unilateral nasal discharge should be investigated for suspected CSF leak. In this chapter, we have discussed anatomy, diagnosis, and management of CSF rhinorrhea.