Introduction: Knowledge on dietary habits, tobacco and alcohol consumption in adolescents is crucial to plan early preventive programs. The objective was to assess the eating habits, physical activity and tobacco and alcohol consumption in adolescents of Buenos Aires, in order to get information on cardiovascular risk factors., Material and Methods: Cross-sectional observational study in adolescents aged 11-16 years of 12 urban and rural, public and private schools of the province of Buenos Aires. An anonymous survey was carried out including demographical data, eating habits, physical activity, smoking and alcohol consumption., Results: 1230 adolescents were surveyed, 46% of rural zones. Of them, 42.5% restrained food intake to control weight; 92% performed physical activity at least 1 h a week; 29.3% were smokers and 38.4% drank alcoholic beverages. Females restrained more food intake (46.3% vs. 37.7%; p=0.003) and were heavier smokers (32.6% vs. 25.2%; p=0.005). Alcohol consumption and smoking were associated (OR 8.27; p<0.001). Having a smoker friend increased almost 4 times the chance of smoking. Alcohol consumption by the best friend (OR 10.0; p<0.001), father o brother also increased chance in the adolescent. Adolescents of rural zones performed less physical activity (89.6% vs. 94.2%; p=0.003) and smoked more cigarettes (32.1% vs. 26.8%; p=0.04)., Conclusions: 42% restrained food intake to control weight, and almost all performed physical activity. Rates of smoking and alcohol consumption were 29.3% and 38.4%, and were strongly associated. Smoking was more common in females and in rural zones, and more associated to alcohol and a smoker friend.