The aim of this paper is to present externalized disorders in children and adolescents, namely attention deficit/hyperactivity disorder, conduct disorders, and oppositional defiant disorder. While they differ in their manifestations, what is common to all of these disorders is insufficient control and orientation towards the environment, in contrast to internalized disorders characterized by excessive self-control and self-orientation. Given that these disorders often involve significant impulsivity and aggression, they substantially disrupt relationships with peers and adults, often leading to misinterpretation of the child's behavior as being naughty, which in turn influences the reactions of the environment and may serve as a maintaining factor for the disorder. Therefore, it is important to recognize these disorders in order to avoid actions that can contribute to the maintenance or even exacerbation of symptoms and to intervene in a timely manner. A further problem is presented by comorbid disorders, which are relatively common but often go unrecognized in these children. Numerous biological and psychosocial risk factors are associated with these disorders, making preventive measures of utmost importance. Special emphasis is placed on ADHD as a biologically conditioned disorder, the manifestations of which can be influenced by psychosocial factors. ADHD is characterized by difficulties in academic, occupational, and social settings. Conduct disorder is defined as a persistent pattern of behavior in which the basic rights of others or important social norms are violated. Oppositional defiant disorder is characterized by a child's negative, hostile, and defiant behavior towards adults and authorities. Various levels of prevention are described, including primary, secondary, and tertiary prevention, with a special focus on the approach to these children in educational institutions.