Cerebrospinal fluid (CSF) rhinorrhoea is well known to the ENT surgeon. It commonly occurs secondary to a predisposing event such as accidental or iatrogenic trauma. When it occurs spontaneously, it can be associated with benign intracranial hypertension. The commonest CSF leak sites are located in the anterior cranial fossa, namely the ethmoid roof, the olfactory groove and the sphenoid sinus roof. The initial management paradigm of CSF leak is partially dependent on the root cause of the predisposing event. Ultimately though, all persistent cases of CSF leak should undergo surgical repair. Historically, these defects have been repaired via an external approach; increasingly however, endoscopic approaches are proving popular. Whichever technique is chosen, one of the fundamental factors underpinning success is localisation of the leak site. Access to both high-resolution CT and MRI imaging increases sensitivity for detecting the leak to almost 97%. CT cisternography is rarely used due to low sensitivity. The availability of perioperative adjuncts such as intra-thecal fluorescein and image-guidance system may further improve the confidence of the surgeon. This review concludes that most leak sites can be successfully repaired endoscopically, with potentially much lower morbidity. Frontal sinus defects are traditionally repaired externally, but the advancement of the 45 and 70° angled telescopes have made possible repair of certain frontal sinus leaks. The final frontiers for endoscopic repair currently are at an extreme superior or lateral location of the frontal sinus, beyond the reach of current instruments.