The paper refers to the functions that the principle of the interest of children and adolescents fulfills in the Chilean Consumer Protection System. At first, its character as a General Principle of Law is recognized, and it is attributed a polyfunctional aptitude, for which is fulfills different roles in the Consumer Law. Its interpretive function is thus stated, which requires that all normative exegesis must be directed towards safeguarding the interest of children and adolescents. In the same way, it serves as a mechanism integration and resolution of legal contradictions. In such context, it allows establishing standards of duties, through the delimitation of the expected social Benefit. Finally it has a political character, by which it inspires behavioral discipline.