Endoscopic sinus surgery for chronic sinus diseases, has been used with an increasing popularity in the last 20 years. As it is considered to be a technique which is most likely to preserve the normal physiology, the term 'functional endoscopie sinus sur-gery' is widely accepted. Yet, endoscopie sinus surgery can not achieve that goal in all patients with chronic sinusitis, particu-larly in nasal polyposis. Patients whose complaints persist despite maximal postoperative medical treatment, should be consi-dered as candidates for revision surgery. If the patients who had underwent traditional sinus surgery are excluded; patients with nasal polyposis constitute the main candidate group for revision surgery. Lateralisation of the middle turbinate, adhesions, and pathologies like polyps that obstruct of cavity ethmoidectomy disrupt ventilation and drainage of the paranasal sinuses and are the main reasons for revision surgery. In this study, fifty patients who had undergone endoscopie sinus surgery for various reasons and followed for 12 to 20 months were evaluated. Fourteen (%28) patients were selected for revision surgery. The fol-low- up duration correlated with the indication for revision surgery. In this paper the reasons for revision surgery and the timing of the surgery are discussed with general analysis of the cases.