Functional endoscopic sinus surgery (FESS) is a surgical modality for some diseases of the nose and paranasal sinuses. It is the mainstay in the surgical treatment of sinusitis and nasal polyposis, including fungal sinusitis.FESS is a relatively recent surgical procedure that uses nasal endoscopes (using Hopkins rod lens telescopes) to minimize cutting and trauma to the skin. They provide good illumination of the inside of the head and can be introduced into the nose after anesthetising.FESS came into existence because of pioneering work of Messerklinger and Stamberger (Graz, Austria.).