Background/Aims: In this retrospective study, we aimed to investigate the prevalence of heterotopic gastric mucosa (HGM) in the upper and middle esophagus, to identify its macroscopic characteristics and evaluate clinical features. Methodology: One hundred and twenty-six patients (82 males, 44 females; mean age 43.08 +/- 12.84 years, range 15-81) with HGM in the upper and middle esophagus diagnosed by gastroscopy and biopsies were admitted to this retrospective study. Disease histories of all patients were carefully inquired, especially the associated complaints including discomfort of throat, heartburn or dysphagia, etc. Results: The prevalence was 0.21%. Patch size ranged between 5-20mm, mean diameter was 7.5 +/- 3.7mm; 80 cases appeared as a single patch; 96.83% had the patch in the upper esophagus. Male gender was pre-dominant (male:female ratio, 1.86), but age was not significant. The mean distance from the incisors to the patch was 18.83 +/- 2.23cm and 17.20 +/- 2.48cm in the male and the female respectively, with a significant difference (t=3.749, p<0.001). In 39 of 126 patients (26 male, 13 female), the esophageal and laryngopharyngeal symptoms were remarkable. Twelve were associated with other diseases of the esophagus. There were no correlations to esophageal symptom, gender, age, location, quantity or diameter. Among the 126 cases, 29 patients were associated with other esophageal diseases. Conclusions: H GM patches in the esophagus should not be overlooked during endoscopy because they may lead to esophageal symptoms and even important complications in relation to their acid secretions.