OBJECTIVE: To investigate the occurrence and association of arterial hypertension with several lifestyle variables. METHODS: Transversal population-based study with a random sample of students (7 to 14 years of age) of public and private schools. Variables investigated were nutritional status, blood pressure, and lifestyle (tobacco use, alcohol intake, physical activity and eating habits). RESULTS: Out of the 3,169 schoolchildren assessed, 5.0% had arterial hypertension and 6.2% had normal-high blood pressure. Classification by gender shows boys 6.4% and girls 6.0% with normal-high blood pressure, and boys 4.3% and girls 5.7% with arterial hypertension. Body mass index (BMI) measurements identified 16.0% excess weight students, 4.9% of whom were obese. A significant association (p = 0.01) between arterial hypertension and excess weight was observed. Among the students participating in the study, 11.6% did not attend physical education classes and 37.8% had sedentary leisure habits. Twenty students (0.6%) were smokers and 32.7% had already experimented with alcohol. None of these variables showed statistical significance as to blood pressure values and nutritional status. CONCLUSION: In light of the findings in this study which show schoolchildren with a higher than expected frequency of mean blood pressure and BMI values, associated with a lifestyle that tends to favour the development of cardiovascular diseases, we felt led to propose interventional measures focused on the school as an agent of change and capable of conveying information to family units. This possibility encourages us to propose that schools be partners in promoting health.