A low socioeconomic level is associated with a greater risk of smoking, drinking, failing courses and not practicing sports in the adolescents. Additionally, the mothers drinking is associated with a greater risk of her children smoking and drinking, and both parents drinking is associated with a greater risk of their children doing so. The practice of sports and the time spent watching television by the parents have an influence on the corresponding habits in their children, but have no influence on the adolescents smoking or drinking.