Chromoendoscopy and magnification endoscopy are 2 endoscopic techniques used to improve visualization and diagnosis of gastrointestinal mucosa. This article summarizes the principles behind magnification endoscopy, with and without chromoendoscopy, for the diagnosis of Barrett's esophagus, dysplasia, and adenocarcinoma. Furthermore, this article discusses the possible clinical use of magnification endoscopy and chromoendoscopy in evaluating patients with chronic gastroesophageal reflux disease and Barrett's esophagus.