Objectives: To determine the prevalence and treatment status of hypertension in South Africa. Design: National cross-sectional survey. Setting : 13 802 randomly selected South Africans, 15 years and older, were visited in their homes in 1998. Methods : Trained fieldworkers completed questionnaires on lifestyle and chronic diseases, measured blood pressure with an Omron manometer and recorded chronic drug utilization. Drugs were classified using the Anatomical Therapeutic Chemical index. Results : The mean systolic blood pressure for men and women was 123 mmHg (SE 0.37) and 119 mmHg (SE 0.36), while the mean diastolic level was 76 mmHg (SE 0.25) and 75 mmHg (SE 0.20), respectively. When using a cut-off point of 140/90 mmHg the hypertension prevalence rate (age-adjusted to the South African Population, Census 1996) was 21% for both genders. Using the current cut-off point (160/95 mmHg) for South Africa, the prevalence rate was 11% for men and 14% for women. For men with hypertension, the level of awareness, taking antihypertensive medication and having controlled blood pressure (< 160/95 mmHg) were 41, 39 and 26% respectively, while for women these rates were 67, 55 and 38% respectively. Conclusions : This survey revealed high levels of hypertension in the South African community with inadequate treatment status.