Background: Chilean aboriginal populations (Mapuche) predominantly live in the region of Araucania, in the southern part of the country. Their cardiovascular risk factors have not been systemically assessed. Aim; To study the prevalence of cardiovascular risk factors in the Mapuche population. Subjects and methods: Blood pressure, weight, height, dietary habits, fasting serum total cholesterol, HDL cholesterol and triglycerides were measured in 1.948 adults living in 28 Mapuche communities. Results: Thirteen percent of males and 16% of females had high blood pressure. Body mass index was 25.5 kg/m(2) in males and 28.1 kg/m(2) in females. Forty five percent of women and 24% of men were classified as obese. Mean serum total cholesterol was 186.7+/-9.6 mg/dl, HDL cholesterol was 58.7+/-30.7 mg/dl, total cholesterol/HDL cholsesterol was 3.4+/-2 and triglycerides were 155+/-91.2 mg/dl. Twenty eight percent of males and 9.6% of females smoked. Conclusions: Mapuche individuals have higher levels of HDL cholesterol, a better total cholesterol/HDL cholesterol ratio and lower frequency of smoking than non aboriginal Chileans subjects.