The relevance of the study is rooted in the persistent tension between state sovereignty and the applicability of human rights guarantees under the European Convention on Human Rights (ECHR), particularly concerning Article 6(1) ECHR. The aim of the article was to explore how the European Court of Human Rights (ECtHR) interprets the application of procedural guarantees in cases involving sovereign state actions. The methodology employed includes a selective analysis of ECtHR case law, focusing on matters involving public and private law and the distinction between acta jure imperii and acta jure gestionis. The article demonstrated that the applicability of Article 6(1) depends significantly on whether the dispute relates to public law matters, such as tax assessments, or private law matters, such as contractual disputes. It was found that the Court generally excludes state actions in sovereign capacities from the scope of Article 6(1), while extending it to cases involving non-sovereign state activities. This distinction underscored the Court's ongoing balancing act between protecting individual rights and respecting state sovereignty. The article concluded that, despite challenges, the evolving jurisprudence of the ECtHR shows a potential for expanding the scope of human rights guarantees under the Convention. The practical value of this research lies in its contribution to the broader understanding of the ECtHR's approach, which can guide future case law and academic discussions regarding the limits of state sovereignty and the application of fair trial guarantees