Barrett's esophagus is an alteration of the esophageal epithelium, regardless of length, evidenced by endoscopic examination (protrusion of the gastric mucosa into the esophagus in the shape of a flame) and confirmed by histological examination of the bioptic samples (intestinal metaplasia with mucosecretory cells). It develops following long-term gastro-esophageal reflux (GER). The documented risk factors are: long-term GER (duration more than 5 years), age over 50 years, male sex, Caucasian race, aggressiveness of the refluxed material, individual susceptibility of the esophageal mucosa to the refluxed material. The carcinogenic risk is 30 times higher than in the general population. Treatment targets the acid reflux, with proton pump inhibitors (PPI), prevention of carcinogenesis with cyclooxygenase 2 inhibitors, ablation of the metaplastic area by laser, plasma-argon mucosectomy, or photodynamic therapy and antireflux surgery.