Coupled to the constitutional principles of the due process of the law and access to justice, the brazilian Child and Adolescent Statute (Estatuto da Criança e do Adolescente - ECA) guarantees full protection to minors under the age of 18. The ECA came into force in 1990 establishing not only specific procedures but introducing the understanding of children and teenagers as subjects of rights. Despite this legal improvement, adolescents in conflict with the law still face extreme discrepancies between their legal rights and the actual reality of the treatment they receive, especially when the socio-educational measures include incarceration. The University Legal Assistance Service (SAJU/UFRGS) is formed by both volunteer students and lawyers and provides free legal assistance to adolescents in conflict with the law. This group has an interdisciplinary approach due to its conformation as it includes not only law students but psychology and education volunteers. This cooperate work aims to a broad and qualified defence during all stages of the legal process. Since the beginning of the group, we’ve been struggling to ensure full compliance with the principles of the legislation and recognition of the human rights. In the matter of juvenile justice, the SAJU/UFRGS has witnessed the process of institutionalization and segregation of socially vulnerable teenagers in Porto Alegre. Furthermore, the amount of constitutional rights violation seen during the working cases of the group has allowed us to create a critical view towards the juvenile justice system. Through a case-by-case analysis, it is manifestly evident that in spite of advanced legislation, the rights guaranteed to adolescents in conflict with the law are allegedly infringed.