Objectives: The primary objective of this study was to determine the association between chronic rhinosinusitis in children (CRS) and extraesophageal laryngopharyngeal reflux (EEGR). Methods: The proposed study was done in Montreal Children Hospital (Montreal, Canada)) from April 2009 till January 2010. Tissue from the paranasal sinus and adenoids were obtained from 14 patients with CRS (age 2-18 years) undergoing endoscopic sinus surgery (ESS) and 18 matched control subjects with no history of CRS (only adenoid tissue) were obtained during adenoidectomy (+/- tonsillectomy). We have used Immunocytochemistry (ICC) to evaluate the presence of pepsinogen in the paranasal sinus tissue of children with CRS group.We have also examined the presence of pepsinogen in adenoid tissue of CRS group and compared them with adenoid tissue of control group. Results: Immunoreactivity for pepsinogen was identified in the epithelial layer of adenoid tissue (50%) and paranasal sinus tissue (65%) in the CRS group. Only occasional staining was observed in the epithelial layer of the adenoid tissue of the control group. Conclusions: The detection of immunoreactivity of pepsinogen in paranasal sinus tissue suggested a possible role of EEGR in CRS in children .