Cardiovascular disease continues to be the principal cause of death in the world. At present, the risk factors for cardiovascular disease continue to appear at an earlier age permitting prevention activities and the promotion of healthy habits to focus on children. Numerous studies have shown that these factors can be controlled in children through school-based interventions. At the same time, data shows that there is a persistence of unhealthy lifestyles (ie sedentary lifestyles, the use of tobacco, etc…) that begin in childhood and are perpetuated until adulthood. Therefore, the acquisition of healthy lifestyles should begin as early as possible. The SI Program for Preschool Education is an intervention that is both school and home based designed to improve the habits, knowledge and attitudes in four key areas: Food (diet), Physical Activity, Knowledge of the Body and Managing Emotions. This intervention will be implemented in children from three to five years of age, in their parents and in their teachers. To evaluate the efficacy of this intervention, the principal aim of the phase of evaluations is to quantify the behavior changes in the three groups/populations mentioned. The evaluation has been designed according to the controlled intervention model, in which twenty-four schools from the Community of Madrid will be randomized to implement the Program si! for Preschool Education or to function as control schools.