BACKGROUND AND OBJECTIVES: The purpose of this study is to determine the prevalence of prehypertension (preHT) among the local residents aged 45 or over, and to compare the differences in demographic factors, anthropometric measurements, life style factors and metabolic profiles between the normotensive (nBP) and preHT individuals. SUBJECTS AND METHODS: The study data was based on the Hallym Aging Study that included 855 adults (356 men and 499 women) aged 45 years or over who lived in Chuncheon city. PreHT was defined by the JNC-7 criteria. We examined the life styles (alcohol, smoking and exercise) of the subjects and we measured the obesity indices. The metabolic profiles are fasting blood glucose (FBS), cholesterol, triglyceride (TG) and HDL-C. The association between preHT and the related factors was examined by using multiple logistic regression analysis. RESULTS: The age-adjusted overall prevalence of preHT is 32.4% (33.6% in men, 31.6% in women). The obesity indices are significantly higher in the preHT group (waist circumference, WC: 87.1+/-8.5 vs 83.3+/-9.3 cm, respectively, p=0.000, waist-hip ratio: 0.93+/-6.6 vs 0.90+/-7.7, respectively, p=0.004, and body mass index: 25.1+/-3.3 vs 23.8+/-3.3 kg/m2, respectively, p=0.001) compared with the nBP group. The metabolic profiles are significantly different for the FBS of the preHT and nBP groups (104.6+/-29.8 vs 96.9+/-21.1 mg/dL, respectively, p=0.005) and TG (160.3+/-82.8 vs 133.4+/-65.3 mg/dL, respectively, p=0.001). The preHT group has more Framingham risk factors and metabolic syndrome components (p=0.003) than the group with a nBP. Important determinants of preHT are a WC> or = 90 cm (OR: 6.28) and a TG> or = 150 mg/dL (OR: 4.33) for men and a BMI> or = 27 kg/m2 (OR: 3.82), a FBS> or =100 mg/dL (OR: 3.05) and a TG> or = 150 mg/dL (OR: 2.69) for women. CONCLUSION: In this study, the preHT group shows a collection of multiple risk factors, including obesity, hyperlipidemia and fasting glucose abnormalities. Early recognition and more intensive life style modification are needed to reduce the risk of cardiovascular disease.