Background: Chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP) is reported to be different in inflammatory patterns of the sinonasal mucosa in white patients. Studies in nonwhite populations may further be helpful to understand the pathogenic mechanisms of CRS. Objective: To investigate the immunopathologic profiles of CRSwNP and CRSsNP in adult Chinese. Methods: Histologic characteristics of surgical samples were analyzed in 50 controls, 94 CRSsNP patients, and 151 CRSwNP patients. Tissue samples from 17 controls, 36 CRSsNP patients, and 45 CRSwNP patients were stained for CD3, CD4, CD8, CD20, CD68, myeloperoxidase, and dendritic cell lysosome-associated membrane protein. Expression profiles of transcription factors of T-cell subsets in relation to cytokines and a marker of natural killer T cell (V alpha 24) were examined by means of quantitative RT-PCR. Results: Over half of CRSwNP patients presented noneosinophilic inflammation. CRSwNP had a higher number of eosinophils, plasma cells, and CD3(+), CD8(+), CD20(+), and CD68(+) cells and a lower myeloperoxidase expression rate than CRSsNP. Expression levels of transcription factors and cytokines of T(H)1/T(H)2/T(H)17 were increased, whereas the expression rate of Forkhead box p3 and TGF-beta 1 was decreased in both CRSsNP and CRSwNP compared with controls. Comparing CRSsNP and CRSwNP, CRSsNP had higher levels of IFN-gamma expression, whereas only eosinophilic CRSwNP demonstrated an enhanced expression of GATA-3 and IL-5. Compared with noneosinophilic CRSwNP, an exaggerated T(H)2/T(H)17 reaction and V alpha 24 expression were found in eosinophilic CRSwNP. Conclusion: Both Chinese CRSsNP and CRSwNP patients demonstrate impaired regulatory T cell function and enhanced T(H)1/T(H)2/T(H)17 responses. CRSsNP is confirmed to be a predominant T(H)1 milieu, whereas T(H)2 skewed inflammation with predominant T(H)17 reactions, and infiltration of natural killer T cells can be demonstrated only in eosinophilic CRSwNP, but not in noneosinophilic CRSwNP. (J Allergy Clin Immunol 2009;124:478-84.)