Eosinophilic esophagitis (EoE) is a rapidly increasing, chronic, T helper 2-type inflammatory disease of the esophagus characterized by esophagus related symptoms and a dense esophageal eosinophilia, both of which are refractory to proton pump inhibitors. The adult patient presents with a typical history of dysphagia for solids and has often experienced food impactions. However the general appearance shows an apparently healthy individual; the physical examination is usually unremarkable. The endoscopic findings are often subtle and misleading. The diagnosis is therefore based on the histologic finding of a dense eosinophilic infiltration of the esophageal mucosa. In adult patients, topical and systemic corticosteroids, leukotriene receptor antagonists, immunomodulators, and dilation have proven efficacy, whereas therapy with diet is still under evaluation.