BACKGROUND: There are many reports that obesity could be associated with gastoesophageal reflux disease (GERD) but the outcomes are controversial and the studies on correlation between endoscopic severity of GERD and obesity are rare. Therefore, we investigated the association between endoscopic severity of GERD and indexes of obesity. METHODS: Among the subjects who visited a health promotion center of a general hospital from January 2007 to March 2008, a total of 527 subjects with typical symptoms of GERD who underwent esophagogastroduodenoscopy and analysis of body composition were enrolled. The endoscopic severity of GERD was classified depending on LA grading classification system. RESULTS: Among 527 subjects, 125 subjects were classified with Non-erosive reflux disease (NERD) while 254, 105, and 43 subjects were classified as LA grade A, B, and C group, respectively. Men and frequent alcohol drinkers (> or = 5 times/week) were likely to be in higher endoscopic severity group (OR, 2.065 and 2.394, respectively; P < 0.05). If the subject was obese by BMI and waist circumference, it showed a higher possibility of belonging to the higher endoscopic severity group (OR, 2.319 and 2.596, respectively; P < 0.001). In the case of %body fat, the obesity group was more likely to be in the higher endoscopic severity group only in men (OR, 1.906; P < 0.001). CONCLUSION: Indexes of obesity such as BMI, %body fat (only in men), and waist circumference were related with endoscopic severity of GERD and this relationship is more apparent in men and alcohol drinkers (> or = 5 times/week).