Purpose of Review <p>Chronic rhinosinusitis (CRS) is a complex inflammatory disease of the nasal and paranasal sinus mucosa, characterized by persistent symptoms and heterogeneous immune responses. This review aims to dissect the immunological mechanisms underlying CRS, focusing on the roles of innate and adaptive immune dysregulation, and to explore recent advancements in therapeutic strategies.</p> Recent Findings <p>Recent studies have highlighted the critical roles of various immune cells in driving CRS pathology. Single-cell RNA sequencing and other omics technologies have provided deeper insights into the cellular and molecular heterogeneity of CRS, revealing distinct endotypes. Key findings include the identification of pathogenic Th2 cells, the role of polyclonal immunoglobulins in local inflammation, and the involvement of epithelial-derived cytokines in amplifying type 2 immune responses. Additionally, novel therapeutic targets, such as biologics targeting IL-4, IL-5, and IL-13, have shown promise in managing CRS, particularly in type 2 CRSwNP.</p> Summary <p>CRS is a multifactorial disease influenced by genetic, environmental, and immunological factors. Advances in understanding the immune mechanisms driving CRS have led to the development of targeted therapies. However, non-type 2 CRS remains a therapeutic challenge, necessitating further research into its underlying mechanisms and the development of personalized treatment approaches.</p>