Barrett's metaplasia of some extent is found commonly in patients with GERD. Detection is possible only by endoscopy and biopsy of the columnar appearing mucosa; no symptoms or signs distinguish patients with Barrett's metaplasia from those without. The management goals in patients with Barrett's are to alleviate reflux symptoms and to control the risk of adenocarcinoma. Symptom control is achieved primarily with PPIs. Acid inhibition does not, however, cause regression of Barrett's metaplasia and has not been shown to reduce the risk of esophageal adenocarcinoma. The risk of adenocarcinoma is managed by surveillance with endoscopy and biopsy searching for dysplastic change. LGD merits more intense surveillance. The optimal management of HGD, however, remains controversial, as evidenced by the multitude of ablation therapies that have been introduced recently. These techniques will be discussed in depth in subsequent articles in this volume.