Background/Aims Prevalence of reflux esophagitis have increased in Western and Eastern countries. The prevalence and disease-characteristics of endoscopic esophagitis in young Japanese individuals are not fully demonstrated. The aim of this study was to determine the prevalence of reflux esophagitis and Helicobacter pylori infection and their relationship in young healthy Japanese volunteers. Methods Upper gastrointestinal endoscopy was performed in 550 young healthy Japanese medical school students,age 21 to 36 years, mean 23.4 years,between 2008 and 2013. Helicobacter pylori infectionwas determined by detecting urinary IgG antibodies. Upper gastric clinical symptoms were monitored with questionnaires of FSSG scales. Results Helicobacter pylori antibodies were detected in 50 of the 550 subjects (9.09%) with endoscopic chronic gastritis without peptic ulcers. Endoscopic reflux esophagitis was detected in 55 out of the 550 subjects (10%), including grade A in 48 subjects (8.7%), grade B in 6 (1.09%) and grade C in 1 (0.18%). Only 5 subject with reflux esophagitis was Helicobacter pylori-positive, and the other 50 subjects with esophagitis were Helicobacter pylori-negative. Infection rate of Helicobacter pylori decreased around 40% during the last 6 years in a time dependent manner, although relatively high prevalence of reflux esophagitis of 10% was not changed during the last 6 year. Several factors were related to the prevalence of reflux esophagitis and most critical risk factors were lifestyles including alcohol consumption and increase in body weight. Clinical symptoms of heartburn were more common and FSSG scales were high in subjects with reflux esophagitis. FSSG scales were not different in subjects with or without Helicobacter pylori infection. Conclusion This study indicated relatively high prevalence (10%) of endoscopic reflux esophagitis in young Japanese adults around 23 years old, and risk factors for esophagitis were alcohol drinking and obesity.