Background: Endoscopic sinus surgery (ESS) is the main surgical approach in the treatment of chronic rhinosinusitis (CRS) after failure of medical treatment. Objective: The goal of this study was to evaluate computed tomography (CT) findings associated endoscopic sinus surgery. Materials and Methods: 17-73 ages of 200 CRS patients who were operated endoscopic sinus surgery at department of ENT of First Central Hospital between November 2019 and November 2020, involved in this study. Subjects were divided into 2 groups: 1) CRS with NP 2) CRS without NP. CT changes were evaluated according to the Lund-Mackay, Hoover score, Hounsfield unit before and after surgery. Statistical analysis was performed with Stata 12.1. Result: Of the total subjects analysed, 112(56%) were male and 88 (44%) were female. Average age of subjects was 38.4±13.9. Male: female gender ratio of patients was 1.27:1. Conclusion Endoscopic sinus surgery for CRS is effective according to the evaluation of Lund-Mackay, Hoover and Hounsfield unit, and it was statistically significant (p<0.0001).