Background/Aims: We aimed to evaluate the hypothesis that the metabolic syndrome (increased waist circumference and two of the following components high blood pressure, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, or diabetes/hyperglycemia) is a risk factor for erosive esophagitis. Methods: A case-control study was performed using a database of Kangbuk Samsung Hospital medical screening center from January to December 2006. Results: A total of 3,243 cases of erosive esophagitis and randomly selected, age, sex matched 6,486 controls were included. Hiatal hernia, smoking, waist circumference, BMI, triglyceride, ALT, reflux symptoms were risks for erosive esophagitis. Metabolic syndrome was diagnosed in 16.6% of cases and 12.8% of controls (P<0.01). And multiple logistic regression confirmed the association between erosive esophagitis and metabolic syndrome (odds ratio 1.44, 95% confidence interval 1.23-1.68), including smoking, hiatal hemia and reflux symptoms. Conclusions: Within the limitations of this case-control study, there is an significant association between erosive esophagitis and metabolic syndrome among Koreans with erosive esophagitis.