Background/aims: Glycogenic acanthosis is described as benign thickening of the esophageal squamous epithelium of unknown etiology. Although its etiology is unknown, it has been reported that glycogenic acanthosis may be related to gastroesophageal reflux and hiatal hernia. The aim of the present study was to review the patients who were diagnosed with glycogenic acanthosis on upper gastrointestinal endoscopy and to determine whether there is any association between glycogenic acanthosis and gastroesophageal reflux and hiatal hernia. Material and Methods: A total of 504 patients who underwent upper gastrointestinal endoscopy for evaluation of non-ulcer dyspepsia were reviewed retrospectively. Results: Glycogenic acanthosis was detected in 143 (28.3%) of those 504 patients. Of the 143 patients, 82 (57.3%) were male and 61 (42.7%) were female. Patients with glycogenic acanthosis were aged 20-83 years. Gastroesophageal reflux was detected in 50 (34.9%) cases with glycogenic acanthosis, while hiatal hernia was detected in 30 (20.9%) cases. Gastroesophageal reflux was detected in 102 (28.2%) control subjects, while hiatal hernia was detected in 50 (13.8%). Hiatal hernia was significantly higher in glycogenic acanthosis patients than in controls subjects (p<0.05). Glycogenic acanthosis patients had higher gastroesophageal reflux than seen in controls subjects, but the difference between groups was not statistically significant (p>0.05). Conclusions: Our results suggest that glycogenic acanthosis is primarily an age-related disease. We demonstrated that glycogenic acanthosis may be associated with gastroesophageal reflux and hiatal hernia. Further studies are necessary to confirm these findings.