Objective. Chronic rhinosinusitis has a negative effect on the quality of life of millions of involved patients. The aim of this study was to assess the effect of endoscopic sinus surgery on the quality of life in patients with chronic rhinosinusitis. Materials and Methods. Twenty-five cases with chronic rhinosinusitis, which were resistant to 12 weeks of medical treatment, underwent Endoscopic Sinus Surgery. Two kinds of health related quality of life (HRQoL) surveys (the Chronic Sinusitis Survey and the Rhinosinusitis Disability Index) were applied to all cases before and at least 6 months after the operation. The LundKennedy endoscopic scoring system was used as an objective evaluation. All analysis was performed using SPSS statistical software. Results. Statistically significant improvements were computed for cases before and after surgery for the Chronic Sinusitis Survey symptom scores (p<0.05). Also, statistically signifi• cant improvements were found for cases using the Rhinosinusitis Disability Index. However, mean changes in endoscopic scores did not statistically correlate with changes in quality of life (p>0.05). Conclusions. Our results showed that endoscopic sinus surgery improves the quality of life in cases with chronic rhinosinusitis. But this improvement did not correlate with the endoscopic scores of the paranasal sinuses.