Restitution, as the primary form of reparation in international law, faces significant theoretical and practical challenges when human rights violations result from the concurrent or interrelated conduct of multiple States. This study examines the evolving concept of restitution within the framework of shared international responsibility by analyzing the jurisprudence of the European Court of Human Rights (ECtHR) and assessing its consistency with the principles governing shared responsibility in international law. The research adopts a descriptive-analytical methodology based on a comprehensive review of international legal instruments, scholarly literature, and an in-depth analysis of leading and recent ECtHR judgments. The findings demonstrate that, through a dynamic interpretation of Article 41 of the European Convention on Human Rights, the Court has progressively expanded the traditional understanding of restitution beyond its material and individual dimensions toward a multidimensional, institutional, and participatory model. Within this framework, measures such as institutional and legislative reforms, effective investigations, guarantees of non-repetition, transnational cooperation among States and regional institutions, and the restoration of confidence in the human rights system have emerged as contemporary forms of restitution. The study further reveals that although the Court has gradually developed a more coherent approach to shared responsibility and restorative justice in its recent case law, jurisdictional limitations and the absence of coordinated enforcement mechanisms continue to impede the full realization of restitution in cases involving multiple responsible States. Accordingly, the study concludes that the development of a more coherent judicial practice, together with strengthened supervisory mechanisms and enhanced international cooperation, constitutes an essential prerequisite for ensuring the effectiveness of restitution within the framework of shared international responsibility