Herpes simplex virus type 2 (HSV-2), which has been recognized as a potential cardiovascular pathogen and implicated in carotid atherosclerosis and coronary artery disease, is independently associated with the future risk of cardiovascular death. Investigations have demonstrated that hypertension may be related to inflammation, and inflammation is one of the symptoms of HSV-2 infection. This cross-sectional study investigated the correlation between HSV-2 infection and essential hypertension. One thousand two hundred and forty four inpatients (488 patients with essential hypertension and 756 normotensives) were investigated serologically for the specific immunoglobulin G (IgG) to HSV-2 by enzyme-linked immunosorbent assay. Patients diagnosed with pheochromocytoma, primary aldosteronism, aorto-arteritis or renal artery stenosis were excluded. The prevalence of HSV-2 IgG seropositivity was significantly higher in the hypertensive group than in the normotensive group (38.3% vs. 29.8%, p =0.002). After adjustment for confounding factors, an association of HSV-2 IgG seropositivity with essential hypertension was found on binary logistic regression analysis. The adjusted odds ratio of essential hypertension was 1.4 (95% confidence intervals, 1.1 to 1.8; p =0.005) for HSV-2 infection; the adjusted covariates included age, male sex, smoking, body mass index, dyslipidemia, diabetes and coronary artery disease. The results of this study indicated that HSV-2 infection might be an independent risk factor for essential hypertension.