BACKGROUND: The prevalence of metabolic syndrome is increasing in Korea. The aim of this study was to establish if there is an association between the presence of metabolic syndrome and the development of gallbladder stones in Koreans. METHODS: Among the subjects who visited a health promotion center of a general hospital from January 2001 to December 2005, a total of 34,574 adults was examined. Among them, the final 34,470 adults (males 20,277, females 14,193) were included. Metabolic syndrome was defined if they fell under the three conditions of BMI > or = 25 kg/m2, blood pressure > or = 130/85 mmHg, fasting glucose 110 mg/dL, triglyceride > or = 150 mmHg and low HDL-cholesterol (< 40 mg/dL in men, < 50 mg/dL in women). After adjusting for age and sex, logistic regression analysis was done to evaluate the relationship between metabolic syndrome and gallstones. RESULTS: This study showed that the prevalence of metabolic syndrome was 17.6% (males 21.1%, females 12.4%). Gallbladder stone risk was increased according to BMI, high blood pressure, high fasting blood glucose and low HDL. Gallbladder stone risk was increased according to clustering of components of metabolic syndrome after adjustment for age and sex (1 criterion: OR = 1.42, 95% CI, 1.20-1.69, P = 0.000; 2 criterion: OR = 1.86, 95% CI, 1.57-2.21, P = 0.000; 3 criterion: OR = 2.02, 95% CI, 1.66-2.45, P = 0.000; 4 criterion: OR = 2.17, 95% CI, 1.66-2.85, P = 0.000; 5 criterion: OR = 2.17, 95% CI, 1.17-4.02, P < 0.014). CONCLUSION: Gallbladder stone risk was increased according to BMI, and increased with people who had combination of more metabolic syndrome components.