Functional Endoscopic Sinus Surgery (FESS) is a procedure routinely performed for chronic rhinosinusitis. The Glasgow Benefit Inventory (GBI), a post interventional questionnaire with General, Social support and Physical Health subscales, was posted to 121 patients. Seventy seven replies were received (63.60%), 31 of the respondents were female and 46 male. Forty four procedures were performed for nasal polyposis and 33 for sinusitis. Overall, 14 patients had unilateral sinus surgery, 63 had bilateral procedures and the mean follow up period was 28 months (range 6 to 55 months). The GBI scores were mainly positive, indicating a benefit from the procedure. On comparing polyposis and sinusitis scores, the difference in the Total GBI and General Subscale scores indicated a greater benefit for polyp disease (p = 0.045 and 0.022). No statistical difference was seen on comparing the scores for female vs. male, by age, bilateral vs. unilateral or by follow up period. This study validates FESS as a procedure for rhinosinusitis as it leads to an improvement in quality of life of patients.