Abstract Introduction Chronic rhinosinusitis (CRS) is a common inflammatory disease. This high prevalence leads to high direct and indirect public healthcosts, which include medical visits, laboratory tests and imaging, pharmacotherapy, hospitalizations, and surgical treatment. Furthermore, CRS has a substantial impact on patientquality of life, affecting productivity and being a common cause of absence from work CRS-associated olfactory dysfunction is highly prevalent, the actual effectiveness of surgical intervention remains inconsistent. Although there are studies evaluating the postoperative course of patients with eosinophilic Chronic rhinosinusitis (eCRS) treated with high-volume budesonide irrigation, there is little objective information regarding the impact of this intervention on olfactory status and quality of life. Objective To conduct a pre- and postoperative analysis of olfaction and quality of life in patients with eCRS treated with surgical intervention followed by high-volume budesonidenasal irrigation. Methods Prospective, descriptive, uncontrolled study of patients with eCRS. All patients underwent pre- and postoperative nasal endoscopy, SNOT-22questionnaire, and the University of PennsylvaniaSmell Identification Text (UPSIT), always by the same previously trained examiner. The SNOT-22questionnaire and the UPSIT were readministered to all patients at 3 months, 6 months, and 1 year postoperatively, and scores compared with those obtained preoperatively. Results Twenty patients were included in the study, 13 males and 7 females, between the ages of 23 and 65; 8 patients had comorbid asthma. Quantitative evaluation using the UPSIT test showed a significant improvement in olfaction 3 months after surgery, which remained 6 months and 1 year after surgery (p = 0.0063). There was no significant association between eosinophil concentrations in polypoid tissue and postoperative SNOT-22 and UPSIT results. Patients with tissueeosinophils >50 had a lower preoperative UPSIT score. As early as 3 months postoperatively, a significant improvement in quality of life was already noticeable, as represented by a decrease in SNOT-22 values, which persisted through the 1-year postoperative follow-up evaluation (p = 0.0005). Quantitative evaluation using the UPSIT test showed a significant improvement in olfaction 3 months after surgery, which remained 6 months and 1 year after surgery (p = 0.0063). Conclusion Surgery effectively controlled eCRS in patientswho adhered to high-volume budesonidenasal irrigation postoperatively. There were significant improvements in quality of life and olfaction, which persisted at least up to one year postoperatively.