BACKGROUND/AIMS: The aims of this study were to evaluate the incidence of reflux esophagitis in patients after a subtotal gastrectomy and to determine risk factors for reflux esophagitis. METHODS: Among 225 patients who underwent a subtotal gastrectomy from June 2003 to December 2004 at Seoul National University Bundang Hospital, 201 patients who received follow-up for more than six months and underwent at least one endoscpoic examination were retrospectively reviewed. We used the Los Angeles (LA) classification system and included a minimal change for reflux esophagitis. RESULTS: There were 173 patients who underwent a Billroth I procedure and 28 patients who underwent a Billroth II procedure. The cumulative incidence of reflux esophagitis was 40.8%. A patient age > or =65 years (p=0.04), a follow-up duration > or =40 months (p=0.03), bile reflux gastritis (p<0.01) and postoperative obesity (p=0.02) were significant risk factors for the development of reflux esophagitis including a minimal change. The number of postoperative endoscopies > or =4 (p=0.012), bile reflux gastritis (p=0.002) and postoperative obesity (p=0.038) were risk factors for a minimal change. A patient age > or =65 years (p=0.04), a follow-up duration > or =40 months (p=0.03) and Helicobacter pylori eradication before surgery (p<0.01) were independent risk factors for LA grade A/B reflux esophagitis. CONCLUSIONS: Bile reflux gastritis is a risk factor for the development of reflux esophagitis after a subtotal gastrectomy. Preoperative helicobacter eradication is also associated with reflux esophagitis, except for a minimal change, but further studies are needed.