The present dissertation aims to analyze the trajectories and modes of participation of children and adolescents in the Conferences on the Rights of Children and Adolescents in the municipality of Rio de Janeiro. We reflect on the factors that hinder and/or facilitate children and adolescents right to participation in the conferences, considering that their participation in these spaces is a complex challenge to be achieved, promoted, and respected. We carried out a Case Studyand conducted semi-structured interviews with 6 adults, and through a focus group, we interviewed 14 adolescents between 16 and 18 years old, as well as a 19 year old youth. Data analysis was conducted using references from the field of Childhood Studies and normative documents related to the right to participation ofchildren and adolescents. The results of the analysis demonstrated that adult-centricism emerges as one of the main obstacles to the realization of a protagonic participation of children and adolescents in this space of deliberation and construction of public policies. The research provided a comprehensive understanding of the various modes of participation of children and adolescents, revealing that even within institutional dynamics dominated by adults, the participation of these individuals is becoming important as catalyst for change.