The aim of this paper is to give a brief overview of the impact of social exclusion as a risk factor on the development of developmental disabilities, especially on the development of behavioural disorders. Also, the paper offers definitions and characteristics of social exclusion with special emphasis on its impact on the lives of children and adolescents. In addition, the development of forms of attachment and the development of behavioural disorders are defined. The impact of attachment on a child's development and other aspects of his life is also commented on. Also, certain behavioural disorders that appear more and more often during the school period and adolescence are highlighted. For this reason, several risk factors for the development of these disorders in children and young people have been listed and presented. Special emphasis was placed on the influence of social exclusion as a risk factor and on the influence of friendship with peers as a protective factor for the emergence of such forms of behaviour. The paper also discusses the possible prevention of social exclusion through the educational system. These impacts are presented through the results of various studies.