OBJECTIVE: About half of the world's burden of cardiovascular disease is carried by countries in the Asia-Pacific region. This study aimed to quantify the contribution of hypertension to cardiovascular diseases (CVD) at the country level, by calculating the sex-specific, population-attributable fractions (PAFs) for fatal ischaemic heart disease (IHD) and stroke (haemorrhagic and ischaemic) for the World Health Organization Western Pacific and South-east Asian regions. METHODS: The most recent sex-specific prevalence data on hypertension were sought. Age-adjusted hazard ratio (HR) estimates for fatal IHD and stroke associated with hypertension were obtained using Cox analyses of individual participant cohort data from 600,000 adult participants in the Asia-Pacific Cohort Studies Collaboration. HR estimates and prevalence were then used to calculate sex-specific PAFs for fatal IHD and stroke, by country. RESULTS: In 15 countries with available data, the prevalence of hypertension ranged from 5-47% in men and from 7-38% in women. Overall, the fraction of IHD attributable to hypertension ranged from 4-28% in men and from 8-39% in women. Corresponding ranges for haemorrhagic stroke were 18-66% and 15-49%, and for ischaemic stroke were 8-44% and 12-45%. CONCLUSIONS: In the Asia-Pacific region, up to 66% of some subtypes of CVD can be attributed to hypertension, underscoring the immense impact that blood pressure- lowering strategies could have in this populous region.