The objective of this study was to estimate mean blood pressure (BP), prevalence of hypertension (defined as BP 140/90 mm Hg) and its awareness, treatment and control in the Vietnamese adult population. This cross-sectional survey took place in eight Vietnamese provinces and cities. Multi-stage stratified sampling was used to select 9832 participants from the general population aged 25 years and over. Trained observers obtained two or three BP measurements from each person, using an automatic sphygmomanometer. Information on socio-geographical factors and anti-hypertensive medications was obtained using a standard questionnaire. The overall prevalence of hypertension was 25.1%, 28.3% in men and 23.1% in women. Among hypertensives, 48.4% were aware of their elevated BP, 29.6% had treatment and 10.7% achieved targeted BP control (<140/90 mm Hg). Among hypertensive aware, 61.1% had treatment, and among hypertensive treated, 36.3% had well control. Hypertension increased with age in both men and women. The hypertension was significantly higher in urban than in rural areas (32.7 vs 17.3%, P<0.001). Hypertension is a major and increasing public health problem in Vietnam. Prevalence among adults is high, whereas the proportions of hypertensives aware, treated and controlled were unacceptably low. These results imply an urgent need to develop national strategies to improve prevention and control of hypertension in Vietnam.