Gastro-esophageal reflux disease (GERD) and chronic rhino-sinusitis (CRS) are prevalent disorders. Coexistence by chance is to be expected in a number of patients. Coexistence due to shared pathogenic mechanisms is controversial. In this paper, we have described the characteristics of GERD and CRS epidemiologically, diagnostically, and pathophysiologically, and reviewed the existing data about a potential role of gastro-esophageal reflux (GER) in the pathogenesis of CRS. A causal link between GERD and CRS has so far not been sufficiently documented. However, some studies do indicate a correlation. Hence, anti-reflux measures should be considered as an option in CRS, particularly in patients where conventional medical and surgical treatment is insufficient.