['Recent studies have shown an association between metabolic syndrome (MetS) and gastric cancer. This study was carried out to assess the effect of MetS on gastric dysplasia in a Korean population presenting for health check-ups.', 'We conducted a retrospective, case-control study on gastric dysplasia between November 2003 and August 2009 at the health screening center. A gastric dysplasia group (N=128) and age-matched, gender-matched control group (N=358) were included. A total of 486 Korean patients aged 20 years or above were assessed for BMI, waist circumference, blood pressure, total cholesterol, low density lipoprotein (LDL)-cholesterol, high density lipoprotein-cholesterol, triglycerides, serum glucose, and HbA1c.', 'In the univariate analysis, fasting glucose, BMI, and the presence of MetS were significant factors associated with the risk of gastric dysplasia. In the multivariate analysis, four of the variables studied (fasting glucose, total cholesterol, LDL-cholesterol, and MetS) had a statistically significant relationship with gastric dysplasia. The risk of gastric dysplasia was associated with modest glucose levels [glucose 100-125 mg/dl; age-adjusted and gender-adjusted relative risk (RR), 2.261; 95% confidence interval (CI), 1.147-4.457; P=0.019], higher total cholesterol levels (total cholesterol ≥240 mg/dl; RR, 6.299; 95% CI, 1.277-31.076; P=0.024), modest LDL-cholesterol levels (LDL 130-159 mg/dl; RR, 0.250; 95% CI, 0.069-0.903; P=0.034), and the presence of MetS (MetS ≥3 components; RR, 2.177; 95% CI, 1.082-4.379; P=0.029).'] Is metabolic syndrome associated with gastric dysplasia?