Rhinosinusitis is the inflammation of nose and paranasal sinuses. FESS is now the most common procedure for the pts of chronic rhinosinusitis who are refractory to medical treatment. Aim: To assess that FESS is the best treatment modality to help patients with CRS who are not responding to medical treatment. Materials and methods: Prospective study of 66 patients those who are treated by FESS from the period of June 2017 to march 2020. Detailled history was taken ,local examination, Xray PNS ,diagnostic endoscopy and CT PNS was done for the evaluation of patient. FESS was then performed and patients were then followed up at first and third week followed by 3 and 6 months. Result: Our study showed that 12 patients were improved by first 3 weeks of FESS,24 by the end of 3 months and 30 patients by the end of 6 months. Improvement on symptomatology is 89% showed improvement in nasal obstruction which was the main complaint and 80% with nasal discharge. Conclusion: The result of the study showed that overall, 90% were benefitted with our gold standard procedure of FESS with minimal complications.