Laboratory testing for a cranial CSF leak is appropriate in patients with otorrhea or rhinorrhea, particularly after trauma or surgery. Neuroimaging is used to confirm the diagnosis of any CSF leak and to ascertain the location of the breach. The β-2 transferrin in CSF is a desialylated form due to the presence of neuraminidase in the central nervous system. Beta (β)-2 transferrin testing is the preferred laboratory approach to assess patients for cranial CSF leaks because it is highly specific and sensitive for CSF secretions. Diagnosis of cranial leaks can be challenging in outpatient and postsurgical contexts, in part because such leaks can be difficult to distinguish from chronic rhinitis. Early diagnosis and intervention, particularly in the case of cranial CSF leaks, are critical to prevent these outcomes. The most severe consequences of a CSF leak are brain abscess or bacterial meningitis due to the passage of bacteria into craniospinal spaces. CSF leaks can also occur spontaneously or in relation to infection, hydrocephalus, congenital malformations, or neoplasms. Tears in the dura mater primarily arise from craniofacial trauma or after procedures such as endoscopic sinus surgery and lumbar puncture. Cerebrospinal fluid (CSF) leaks (also known as CSF fistulas) result from dura mater defects or tears that enable CSF to escape containment.