Chronic inflammation and endothelial dysfunction may be associated with hypertension and cardiovascular disease. We examined associations between inflammatory and endothelial dysfunction biomarkers and the risk of prehypertension among Mongolians. A cross-sectional study was conducted among 2589 Mongolians aged 20 years and older in Inner Mongolia, China. Three blood pressure measurements, body weight, height and lifestyle factors were obtained for all participants. Overnight fasting blood samples were obtained to measure the biomarkers, including C-reactive protein (CRP), soluble intercellular adhesion molecule-1 (sICAM-1), soluble E-selectin (sE-selectin) and angiotensin II. The average levels of CRP (7.43 vs. 5.86), sICAM-1 (339.38 vs. 328.05), sE-selectin (19.11 vs. 18.32) and angiotensin II (52.00 vs. 47.00) were all significantly higher in hypertensives than that in prehypertensives (all P<0.05); prehypertensives had higher levels of CRP (5.86 vs. 4.85) and sICAM-1 (328.05 vs. 314.14) compared with normotensives (both P<0.05). Hypertension (odds ratio (OR): 1.50, 95% confidence interval (CI): 1.07, 2.11) and prehypertension (OR: 1.38, 95% CI: 1.02, 1.85) were positively and significantly associated with elevated CRP adjusted for multivariable. Hypertension (OR: 1.56, 95% CI: 1.18, 2.06) and prehypertension (OR: 1.32, 95% CI: 1.02, 1.71) were also positively and significantly associated with higher sICAM-1 adjusted for age and gender. Elevated CRP and sICAM-1 were associated with prehypertension among Mongolian population. This study suggests that inflammation and endothelial dysfunction may have a role in the development of hypertension.