Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal disorders. The key feature of GERD is reflux of gastric contents into the esophagus. Medical treatment with proton-pump inhibitors (PPIs) is well established and is considered the standard treatment. Given the high prevalence of the condition and the excellent response to medical therapy, antireflux surgery is an option for patients with volume reflux that is not properly controlled by medical therapy. Adenocarcinoma is a rare but life-threatening complication of GERD. The only known precursor lesion for esophageal adenocarcinoma is Barrett's esophagus. In recent years, a clearer understanding of the development of Barrett's and of its progression toward invasive cancer has developed. Genetic factors almost certainly determine the individual risk. The length of the Barrett's esophagus segment and the size of a hiatal hernia are associated with the risk of developing high-grade dysplasia and esophageal adenocarcinoma.With regard to the clinical management of GERD patients with Barrett's, endoscopic surveillance at 3-year intervals is now considered appropriate in the absence of dysplasia. In patients with high-grade dyspepsia, the situation is more difficult. While a considerable proportion of these patients may already have invasive cancers, there is also the possibility that there is only focal dysplasia. For this reason, it is justifiable to carry out curative endoscopic resection. Mucosal ablation procedures may also be appropriate, but these still need to be properly investigated in clinical trials.