Barrett’s esophagus (BE), a well-known complication of gastro-esophageal reflux (GERD), constitutes a precancerous condition for adenocarcinoma of the distal esophagus. Barrett’s carcinoma shows increasing incidences in countries of the western hemisphere; new data, however, indicate that the rise in incidence is not quite as dramatic as previously assumed. Dysplastic changes in Barrett’s epithelium are considered the most important risk factor for the development of Barrett’s adenocarcinoma; recently, dysplasia was subclassified into a more frequent adenomatous (intestinal) and a non-adenomatous (gastric-foveolar) type. H&E staining still is the gold standard for diagnosing dysplasia. Current data show better interobserver agreement in endoscopical resection specimens than in biopsies. Nevertheless, the histological diagnosis of Barrett’s dysplasia should be corroborated by a second opinion because of its clinical consequences. Even though a multitude of biomarkers for increased risk of progression to cancer has been investigated, only DNA content (flow cytometry) and mutations/LOH of chromosome 17p have been proven as consistent markers of increased risk of progression to cancer. Further prospective clinical trials are needed to establish other indicators of progression, marker panels appear to be of better use than single markers.