Chronic rhinosinusitis (CRS) is a chronic inflammatory process of nasal mucosa and paranasal sinuses, lasting more than 12 weeks, without complete resolution of symptoms. CRS is treated medically, followed by Endoscopic sinus surgery (ESS) if necessary, and supplemented by post-operative topical treatment with highly variable clinical outcomes. However, till date there is no consensus on the composition and duration of maximal medical treatment. Despite proven role of topical steroids, the mode of delivery, dose and duration of topical intranasal corticosteroids still remains debatable. Studies found that high volume sinonasal irrigation (> 50 ml) using budesonide is most efficient method but still there is not sufficient data to prove this and results are variable with multiple modifiable factors therefore, this study has been conducted. (1) To determine the difference in mean decrease in Lund-Kennedy endoscopic scores and SNOT-22 scores among post ESS patients with high volume budesonide nasal irrigation nasal cavity and control nasal cavity of chronic rhinosinusitis patients. (2) To determine safety by measuring serum cortisol levels and intra ocular pressure. This is hospital based interventional, randomised, double blind, control trial study. A total of 66 patients of CRS with previous failed medical therapy were included. Same patients nasal cavities were divided into control and case nasal cavities, to avoid demographic bias. All subjects had a baseline SNOT-22 scores (Sino Nasal Outcome Test scores), Lund Kennedy endoscopy score, NCCT PNS score. All patients were undergone ESS procedure. After nasal pack removal, nasal cavities were randomly assigned 1:1 to receive normal saline irrigation (control group) or 1 mg of budesonide irrigation (case group) for transnasal irrigation twice daily for 12 weeks. A total of 66 patients with 132 nasal cavities were included in the study. Out of which 16 were female and 50 were male with mean age 33 year and mean duration of symptoms was 38.19 months. Mean duration of follow up was for 3 months. Mean decrement in SNOT-22 score in control nasal cavity from 52.54(16.309) to 30.06 (18.16) and in endoscopic score from 6.53 (1.33) to 3.93 (1.6) which is statically significant ( value < 0.05) in both scores. Mean decrement in SNOT-22 score in case nasal cavity from 53.73 (15.75) to 21.15 (13.52) and in endoscopic score from 6.74 (1.8) to 2.77 (1.4) which is statically significant ( value < 0.05) in both scores. Decrement in SNOT-22 scores and endoscopy scores in case nasal cavity in comparision to control nasal cavity were compared by student 't' test and found to be statically significant ( value equals to 0.0001). In subjective outcomes 57.57% shows total improvement in control nasal cavities while 72.73% case nasal cavities shows total improvement. Our study shows high volume budesonide irrigation is safe and superior over normal saline irrigation and results were statistically comparable. Still further studies with larger sample size and longer duration of irrigation needed.Based on available evidence, high volume budesonide irrigation is statically safe and superior over normal saline irrigation.