Barrett's esophagus (BE) is a chronic disease secondary to the presence of stomach acid into the esophagus. This atypical situation produces an inflammation and ulceration of the distal esophagus mucosa. It is the main factor predisposing to the development of esophageal adenocarcinoma, which has a very poor prognosis. At present, therapy of Barrett's esophagus is based on acid secretion inhibition with proton pump inhibitors, which is a very effective therapy to reduce gastroesophageal reflux. However, this therapy does not completely eliminate this risk. Therefore, the better way to follow this disorder is to perform periodic upper gastrointestinal endoscopy and biopsies. Therefore, it is necessary to find new chemo-preventive agents that avoid more efficiently the neoplastic progression of BE. New advances in knowledge about BE suggest that antioxidants could be used to reduce the disorder development. These drugs are being used for long time ago in different pathologies in a lot of countries. One of these drugs is melatonin, which combines several characteristics that suggest it could be the most suitable antioxidant. It has no adverse effects reported.