Objective: To evaluate the differences in clinical features and expression of cytokine thymic stromal lymphopoetin (TSLP) and its receptors in patients with eosinophilic and non-eosinophilic chronic rhinosinusitis (ECRS and NECRS). Method: 36 ECRS patients and 50 NECRS patients were evaluated for symptoms, nasal sinus computed tomography scanning, nasal endoscopy, skin prick test (SPT) positivity, and total IgE. Expression of TSLP and receptors in ethmoid sinus mucosa from the ECRS and NECRS groups were investigated by using immunohistochemical staining. Results: ECRS patients demonstrated significantly higher scores of cough and hyposmia. 66.7% of ECRS patients also demonstrated nasal polyps, compared to 50% of NECRS patients, with significantly higher polyp endoscopy scores. 80.6% of ECRS patients demonstrated SPT positivity, compared to 14% of NECRS patients. The overall expression of TSLP, TSLP receptors and IL-7R was significantly greater in eosinophils in the mucosa of ECRS patients than in NECRS patients. The expression of TSLP and receptors in SPT-positive ECRS patients was significantly greater than in SPT-negative patients, with a significant correlation noted between the expression of TSLP and nasal polyp scores. Conclusion: The clinical manifestations of ECRS are likely to be influenced by atopic status of an individual and TSLP-mediated eosinophil infiltration of the rhinosinusoidal mucosa. Copyright (C) 2013 S. Karger AG, Basel