Background:Chronic rhinosinusitis (CRS) significantly affects quality of life, and endoscopic sinus surgery (ESS) is a well-established treatment for refractory cases. However, its outcomes in patients with immunoglobulin deficiencies, such as common variable immunodeficiency (CVID) and selective IgA deficiency, remain underexplored.Objective:To evaluate the outcomes of ESS in CRS patients with immunoglobulin deficiencies, focusing on symptom improvement, radiological findings, and complication rates.Methods:This retrospective study included 185 CRS patients with documented immunoglobulin deficiencies who underwent ESS. Pre-operative and post-operative assessments, including symptom severity, Lund-Mackay scores, and complications, were analyzed. Statistical analysis was performed using SPSS v29.0, with p-values <0.05 considered significant.Results:Significant symptom improvement was reported in 84.3% of patients, with a reduction in mean Lund-Mackay scores from 18.2 ± 3.1 pre-operatively to 9.6 ± 2.8 post-operatively (p < 0.001). Symptom recurrence occurred in 18.4% of patients, and 6.5% required revision surgeries. Immediate and delayed complications were observed in 4.9% and 3.8% of cases, respectively. Patients with CVID exhibited higher recurrence rates (22.5%) compared to those with selective IgA deficiency (10.8%).Conclusion:ESS is an effective and safe treatment for CRS in patients with immunoglobulin deficiencies, providing significant symptom relief and radiological improvement. However, higher recurrence rates and complications in this population necessitate tailored postoperative care and multidisciplinary management.