Gastric juice that refluxes into the esophagus can injure esophageal squamous epithelium. When the injury heals through a metaplastic process in which an abnormal columnar epithelium replaces the injured squamous one, the resulting condition is called Barrett's esophagus. Gastroesophageal reflux disease and Barrett's esophagus are the most important risk factors for esophageal adenocarcinoma. This article examines such issues as the treatment, endoscopic surveillance, and chemoprevention of Barrett's esophagus. Also included are published guidelines and recommendations.