Recent lipid research has focused on low-density lipoprotein (LDL) subfractions as new markers for cardiovascular risk. However, the clinical significance of measurement of LDL subfractions in subjects with essential hypertension is yet to be established. We studied the association between the prevalence of silent lacunar infarction (SLI) and LDL subfractions in patients with essential hypertension. We performed brain MRI to detect SLI and measured LDL subfractions in 100 asymptomatic non-diabetic middle-aged subjects with essential hypertension (mean age, 62 years). We fractionated LDL into three parts, LDL-1, LDL-2, and LDL-3, with LDL-3 being the oxidized subfraction. Of the 100 study subjects, 24 (24%) had one or more SLIs, while the remaining 76 (76%) were considered as a non-SLI group. The LDL-3 levels were significantly higher in the SLI group than in the non-SLI group (8.3 +/- 4.4 mg/dl vs. 6.3 +/- 2.0 mg/dl, p = 0.006). Multiple logistic regression analysis showed that LDL-3 levels alone were an independent predictor of SLI (odds ratio [OR]: 1.380; 95% confidence interval [CI]: 1.113-1.663; p = 0.003). When subjects were divided into quartiles based on LDL-3 levels, the prevalence of SLI was significantly higher in the highest LDL-3 level group than in the lowest LDL-3 level group (p = 0.0036). The present study suggests that LDL-3 levels are associated with the prevalence of SLI in subjects with essential hypertension.