Endoscopic sinus surgery (ESS) is a standard treatment forrhinosinusitis, which failed optimum medical therapy.Iatrogenic cerebrospinal fluid (CSF) rhinorrhoea can occurduring ESS warrants early repair of the leakage. Thecommon sites for CSF leakage are cribriform plate, foveaethmoidalis, and anterior ethmoid sinuses. We present fivecases of iatrogenic CSF rhinorrhoea due to ESS and itsmanagement.