There is a growing evidence that gastroesophageal reflux disease is related to several upper gastrointestinal cancers, mainly the esophageal adenocarcinoma and a certain type of gastric cardia adenocarcinoma. Currently, the incidence of gastroesophageal reflux disease is rapidly increasing in Korea. Therefore, there is a possibility of such increasing cancerous incidents, similar to the western worlds. In this article, the relationship between gastroesophageal reflux disease and several upper gastrointestinal cancers, the components of refluxate which has possible causal relationship with carcinogenesis, and the clinical implications of such relationship in the management of gastroesophageal reflux disease patients are discussed through the review of literature.