Background. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (BP) provides guideline for the new category of BP levels as normal, prehypertension (PHT), and hypertension. Although PHT is associated with a markedly increased risk of developing hypertension within 4 years, its prognostic significance and predisposition to target-organ damage is unknown. Accordingly, we evaluated the effects of normal BP, PHT and hypertension on left ventricular (LV) diastolic function and aortic elasticity, which are sensitive indicators of target-organ damage. Methods. We evaluated LV diastolic function and aortic elastic properties of 60 subjects with PHT, 70 patients with hypertension and 50 normotensive healthy volunteers using transthoracic echocardiography. None of the subjects had any systemic disease. Results. LV diastolic function was more significantly impaired in the hypertension group than in the PHT group compared with controls, but it was not strongly different between the PHT and control group. Aortic distensibility was significantly lower, and aortic stiffness index was significantly higher in both the hypertension and the PHT group than those in the control group. However, aortic elastic properties did not significantly differ between the PHT and hypertension groups. Furthermore, we found that the presence of the PHT was significant predictor of impaired aortic elasticity in a multivariable model that adjusted for other variables. Conclusions. Aortic elastic properties are significantly and LV diastolic function is slightly impaired in subjects with PHT, and impairment of aortic elasticity is as severe as that in hypertension.