Abstract Background: Chronic rhinosinusitis is the most common otolaryngologic disease that has a great impact on patient’s quality of life. Patients refractory to medical therapy require functional endoscopic sinus surgery (FESS). Aim: To evaluate and compare the disease specific quality of life in patients of chronic rhinosinusitis pre operatively and after FESS using the Sino Nasal Outcome Test 22 (SNOT 22). Patients and Methods: This prospective longitudinal study was conducted on 30 patients with chronic rhinosinusitis. History, clinical, diagnostic sinonasal endoscopy and radiological findings were recorded. For assessing the quality of life, the SNOT-22 questionnaire was used preoperatively and after 1 week, 1 month and 3 months after undergoing FESS. Results: About 43.3% of the patients were males and 56.7% were females. Seventy percentage were between 18 and 30 years. Nasal obstruction was the most common presenting symptom (96.6%), followed by nasal discharge (80%). Diagnostic sinonasal endoscopy and non-contrast computed tomography scan of paranasal sinuses reflected the extent of the disease. The mean pre-operative SNOT-22 score was 40.4 ± 12.06 and a decrease in mean post-operatives scores was observed during their post-operative visits at 1 week (11.77 ± 3.39), 1 month (4.67 ± 2.77) and 3 months (2.47 ± 1.28) which were statistically significant. Conclusion: Chronic rhinosinusitis patient’s refractory to medical treatment showed statistically significant improvement in their quality of life after undergoing FESS.