Barrett’s esophagus is precancerous condition in which metaplastic change from squamous to glandular epithelium of distal tubular esophagus is encountered, as a result of chronic gas­troesophageal reflux disease. Adenocarcinoma arises in 0,5-1% of patients with Barrett’s esoph­agus, with growing frequency in the western population. The developement of adenocarcinoma from Barrett’s esophagus is slow and gradual, starting from low-grade through high grade epithelial dysplasia. The aim of this article is to bring close the scope of morphological changes in glandular mucosa in its gradual evolution to adenocarcinoma to medical students, espe­cially in light of growing number of control biopsies during endoscopic follow-up of patients with Barrett’s esophagus.