Objectives : This clinical study was done to examine metabolic syndrome (MS) and plasma homocysteine (HCY) level in patients with silent lacunar infarction (SLI) and in normal controls. Methods : A total of 154 patients, who were over 20 years of age and visited the stroke prevention check-up center of a university hospital from December 2006 to December 2010, were examined by brain CT or brain MRI, and classified into two groups. We compared the components of MS and HCY levels between patients with SLI (n=74) and normal controls (n=80). Modified ATP III definition was used for diagnosis of MS while Korean standard for waist circumference was used. Results : Prevalence of MS was significantly higher in the SLI group than the normal group. HCY was also significantly higher in the SLI group than the noraml, and the odds ratio (OR) for SLI, comparing high HCY level (${geq}10{mu}mol/L$) with low HCY level ($<10{mu}mol/L$), was 3.64 (95% confidence interval (CI); 1.81-7.29, p<.0001). However, there was no correlation between MS and HCY in the SLI group. Prevalence of diabetes and hypertension (HT) was higher in the SLI group than the normal group, but there was no significant difference in blood lipids level between the SLI and normal groups. Of note, HT itself was enough to be an independent risk factor for SLI (OR; 4.58, 95% CI; 1.91-11.01, p=0.001). Body mass index, waist circumference, waist-hip ratio and visceral fat area were significantly higher in the SLI than normal group, and visceral fat area was enough to be an independent risk factor for SLI (OR; 2.41, 95% CI; 1.04-5.59, p=0.040). Conclusions : SLI is shown to have significant correlation with HCY and prevalence of MS, however there is no relationship between HCY and prevalence of MS in patients with SLI.