The article analyzes the particularities of the development involved in the psychosocial integration of children and adolescents with Down Syndrome (DS), which is the most common chromosomal disorder with an estimated worldwide incidence of 1/600 to 1/1000 births. When analyzing the psychological phenotype of DS, two things should be considered: first, the general deficit in intelligence and cognition and, second, the specific DS problems, which distinguish it from other forms of mental retardation, including also its relation to psychosocial integration. Psychosocial integration seems to be a major concern in the lives of people with DS and those who care for them. The particularities of development that influence the process of psychosocial integration analyzed in the paper, refer to the affectivity and communication capacities; how to interact with the social environment, especially with peers; developing the image and self-concept; acquiring social normativity with reference to children and adolescents with DS. Psychosocial integration, which is a continuous process that is customized in specific relational contexts and at different levels of interaction with the environment, begins with the birth of the child, and although it cannot be separated in the analysis of the pre-adolescence periods, that is, in adolescence, it manifests itself impetuously. The most prominent difficulties of psychosocial integration of adolescents with DS are the deficiency in the pragmatic language and the expressive-emotional manifestations, the inability to tart adequately the interlocutors in communication and the complex interpretation of the verbal and non-verbal stimuli, the errors of self-evaluation and self-image, of the prescription of social environment, the low receptivity to social incentives.