Based on a survey in two country towns of southeastern Australia, cardiovascular risk-factor prevalence data from Aborigines and persons of European descent are presented. The mean diastolic blood pressure in 123 Aboriginal males was 83.2 mmHg, compared with 79.2 mmHg in 272 European males (P = 0.005). In 178 Aboriginal females, mean diastolic pressure was 79.2 mmHg, compared with 76.3 mmHg in 281 European females (P = 0.006). Mean plasma total cholesterol was higher in Europeans (both males and females: 5.7 mmol/L) than in Aborigines (in males 5.2 and females 5.0 mmol/L) (male comparison, P = 0.02, female comparison, P < 0.001). The prevalence in participants aged 25 to 64 years of at least one major risk factor (diastolic blood pressure 95 mmHg or higher, plasma cholesterol 6.5 mmol/L or higher, or smoking more than one cigarette daily) was higher in both these samples of Aborigines (94 per cent in males, 89 per cent in females) and Europeans (70 per cent in males, 59 per cent in females) than in the 1989 urban sample of the National Heart Foundation (47 per cent in males, 36 per cent in females). Multivariate analyses showed statistically significant independent contributions of body mass index and the variable 'ethnicity' (unidentified genetic and environmental differences between the groups) to blood pressure and other risk factors. The higher cardiovascular mortality of Aborigines may be explained partly by the higher prevalence of risk factors in this group compared with other Australians. Further, the risk-factor profile may be worse among rural compared with urban Europeans.