Transformations in family structures have led to parental authority being understood as a duty of care and comprehensive protection of children, grounded in the 1988 Constitution and the Statute of Children and Adolescents (ECA). In contexts of contentious separations, communication difficulties and disputes between parents can compromise the balanced exercise of these responsibilities, affecting the development of children and adolescents. In this scenario, mechanisms such as mediation and the intervention of the Judiciary are essential to guarantee the best interests of children, although challenges remain in the practical effectiveness of the legislation. The general objective of this work was to analyze the exercise of parental authority in contexts of contentious separations, seeking to identify the main legal, emotional, and social challenges that interfere with the realization of the rights of children and adolescents, as well as to evaluate the legal and extrajudicial mechanisms capable of contributing to the comprehensive protection foreseen in Brazilian legislation. It has been found that instruments such as family mediation, shared custody, and actions guided by the principle of the best interests of the child are capable of mitigating these effects, provided they are accompanied by interdisciplinary support and judicial policies structured for self-resolution.