The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure defined blood pressure (BP) levels of 120 to 139/80 to 89 mm Hg as prehypertension and those of >= 140/90 mm Hg as hypertension. Hypertension can be divided into 3 categories, isolated diastolic (IDH; systolic BP <140 mm Hg and diastolic BP >= 90 mmHg), isolated systolic (systolic BP >= 140 mm Hg and diastolic BP <90 mmHg), and systolic-diastolic hypertension (systolic BP >= 140 mm Hg and diastolic BP >= 90 mmHg). Although there is clear evidence that isolated systolic hypertension and systolic-diastolic hypertension increase the risks of future vascular events, there remains uncertainty about the effects of IDH. The objective was to determine the effects of prehypertension and hypertension subtypes (IDH, isolated systolic hypertension, and systolic-diastolic hypertension) on the risks of cardiovascular disease (CVD) in the Asia-Pacific Region. The Asia Pacific Cohort Studies Collaboration is an individual participant data overview of cohort studies in the region. This analysis included a total of 346570 participants from 36 cohort studies. Outcomes were fatal and nonfatal CVD. The relationship between BP categories and CVD was explored using a Cox proportional hazards model adjusted for age, cholesterol, and smoking and stratified by sex and study. Compared with normal BP (<120/80 mmHg), hazard ratios (95% CIs) for CVD were 1.41 (1.31-1.53) for prehypertension, 1.81 (1.61-2.04) for IDH, 2.18 (2.00-2.37) for isolated systolic hypertension, and 3.42 (3.17-3.70) for systolic-diastolic hypertension. Separately significant effects of prehypertension and hypertension subtypes were also observed for coronary heart disease, ischemic stroke, and hemorrhagic stroke. In the Asia-Pacific region, prehypertension and all hypertension subtypes, including IDH, thus clearly predicted increased risks of CVD. (Hypertension. 2012;59:1118-1123.). Online Data Supplement