Background: Gastroesophageal reflux disease (GERD) is one of the most prevalent disorders affecting gastrointestinal tract with a wide range of frequency around the world. In this study, we aimed to review all of the published studies about GERD′s prevalence in Iran systematically. Methods: We searched bibliographic databases including PubMed and Google Scholar and local databases (Scientific Information Database and Iran Medex) to achieve all relevant articles to our subject and included them based on predefined inclusion criteria. Results: Twenty-two articles were included in the study to estimate the prevalence of GERD in Iran. Based on these articles, the prevalence of GERD in Iran was within the range of 1.9 to 52%. Conclusions: Due to the differences between studies, such as characteristics of the sampled population and the diagnostic criteria, the reported prevalence of GERD was remarkably different in the reviewed studies. Nonetheless, because of the high prevalence of GERD in Iran, conducting large-scale epidemiological studies should be considered to determine factors associated with the prevalence of GERD to prevent and control it.