OBJECTIVE Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder of the esophagus. Similar to asthma, EoE can induce irreversible structural changes in the esophagus as a result of chronic and persistent eosinophilic inflammation. The aim of this study was to analyse changes in symptoms, eosinophil counts and endoscopic findings after treatment. METHODS Nine patients with EoE (6 men and 3 women; mean age, 36.44 years) were diagnosed with EoE based on typical symptoms, endoscopic abnormalities and infiltration of the esophageal epithelium with ≥ 15 eosinophils/high-power field. The average endoscopic follow-up period was 10 months, ranging from 1 to 25 months. Symptoms and endoscopic and pathological findings at initial observation and follow-up were evaluated. RESULTS Seven of the 9 patients had dysphagia symptoms, which improved in 4 of 6 patients who were treated with proton pump inhibitor. Two patients were unresponsive to proton pump inhibitor and another 2 patients were treated with corticosteroid, which led to symptomatic relief. In 8 patients, esophageal eosinophilia was improved histologically at follow-up after treatment. Six of the 9 patients had typical endoscopic findings of EoE at initial examination. Despite treatment, these findings remained in 5 of the 6 patients at follow-up endoscopy. CONCLUSIONS After treatment, the symptoms and eosinophil counts were temporarily improved, but the endoscopic findings of EoE were generally not improved. This indicates that deformity of esophageal structure due to eosinophilic inflammation might be irreversible despite proper management.