BACKGROUND AND OBJECTIVES: Prehypertension (preHT) is considered to a precursor of hypertension and it is a predictor of excessive cardiovascular risk. We investigated the rates and determinants of progression to hypertension (HT) among local residents aged 45 or over, and we compared the differences in demographic factors, anthropometric measurements, life styles and metabolic profiles between the progression individuals and non-progression individuals. SUBJECTS AND METHODS: Data from the Hallym Aging Study, which was conducted 3 years apart were used to form the sample of 489 adults. PreHT was defined by the Joint National Committee (JNC-7) criteria. We conducted interviews to determine the life style (alcohol, smoking and exercise) and the measured obesity indices. The metabolic profiles were fasting blood sugar (FBS), cholesterol, triglyceride and high density lipoprotein (HDL)-Cholesterol. The factors related to progression to HT were examined by using multiple logistic regression analysis. RESULTS: The progression rate to HT was 56.4% (56.9% in men, 55.9% in women). The presence of metabolic syndrome was significantly greater and the body mass index (BMI) and systolic blood pressure were significantly higher in the progression group compared with the non-progression group (p=0.0475, p=0.0099, p=0.0082, respectively). Important determinants of progression to HT are a BMI> or =25 kg/m(2) [odds ratio (OR): 2.26, 95% confidence interval (CI): 1.02-5.22] and a diastolic blood pressure of 85-89 mmHg (OR: 6.11, CI: 1.55-24.13). Changes of FBS (deltaFBS) and pulse pressure (deltaPP) according to a time interval of 3 years are the significant related factors (OR: 3.40, CI: 1.04-11.13 and OR: 9.40, CI: 2.19-40.12, respectively). CONCLUSION: PreHT frequently progresses to HT over a period of 3 years. A higher BMI and diastolic blood pressure at the index survey are significantly related to progression. deltaFBS and deltaPP are also important determinants. Therefore, early recognition of preHT and intensive life style modification are needed to prevent progression to HT.