Background: Hypertension or elevated blood pressure is often referred to as a silent killer because it usually does not show significant signs and symptoms. So that most patients are not aware if they suffer from hypertension. Based on data from Riskesdas in 2007 it was found out that the prevalence of hypertension incidence of population with age 18 years and over in Indonesia is 31,7%. DIY province itself is one of the provinces whose hypertension prevalence is higher than the national rate of 35.8%. Because of the increasing prevalence of hypertension in adolescence, prevention is necessary. This study aims to determine the relationship between demographic factors and body mass index with hypertensive prevention behavior in adolescents. Method: This research is a non-experimental research with cross sectional approach with 80 respondents from 386 population. Data collection was done by giving validated questionnaire and containing daily activity question related to hypertension prevention behavior. The data is then analyzed using Chi Square test. Results: The results showed that as many as 48 (60%) of respondents had good hypertension prevention behavior and as many as 32 (40%) respondents had poor hypertension prevention behavior. Chi Square test shows that demography factor (age, and department class) is not related to hypertension prevention behavior with p = 0,315 and 0,099 where p> 0,05. While demography factor (gender and address) and body mass index correlated with hypertension prevention behavior with p value = 0,035; 0.044; and 0.019. Conclusion: Demographic factors (sex and address) as well as body mass index are related to hypertensive prevention behavior. While demographic factors (age and class of majors) are not related to hypertensive prevention behavior.