BACKGROUND: Reliable, large-scale, population-based data on blood pressure for Australian Aboriginal and Torres Strait Islander populations are limited. This present study aims to describe the blood pressure levels and to explore the clinical risk factors for hypertension among Australian Aboriginal and Torres Strait Islander peoples. DESIGN: A cross-sectional population survey was conducted in isolated communities in northern and central Australia. METHODS: Australian Aboriginal people (n = 1088) and Torres Strait Islanders (n = 606) aged 15 years and over were examined between 1993 and 1997. Blood pressure, body mass index, plasma glucose and urinary albumin-creatinine ratio were measured. The association of systolic, diastolic and pulse blood pressure to age was determined and independent associations of hypertension with other clinical variables were tested using logistic regression. Comparisons with results from other Australian data (including AusDiab) were made. RESULTS: Systolic blood pressure and pulse pressure increased in a linear manner with age but mean diastolic blood pressure leveled off at around 50 years and decreased thereafter, suggestive of arterial stiffening. The age-standardized prevalence of hypertension (blood pressure > or = 140/90 mmHg or medication) for subjects aged 25-54 years was 27%, compared with 9% in non-Indigenous Australians in the Northern Territory and Queensland (AusDiab Survey). Older age, male sex, higher body mass index, albumin-creatinine ratio and diabetes were independently associated with hypertension. CONCLUSIONS: Elevated blood pressure is a public health concern for indigenous people, which again highlights health differentials in Australia. Early detection and management of high blood pressure should be assigned a high priority in Indigenous communities.