The aim of the article was to analyse the mechanisms of international legal assistance that ensure the protection of the rights of Ukrainian companies in cross-border commercial relations. The study used an interdisciplinary approach combining comparative-legal, systemic-structural, formal-legal and case-study methods, based on the analysis of international conventions and acts, Ukrainian legislation, and the case law of the European Union, the United Kingdom and the United States of America. As a result of the study, the theoretical and legal foundations of the functioning of the institution of international legal assistance to business were systematised as a structural element of private international law that ensures the realisation of the rights of business entities in cross border disputes. It was identified that the national legislation of Ukraine implements these standards, ensuring the effective application in judicial practice. In the course of the analysis, five basic principles of international legal assistance were generalised – reciprocity, sovereign equality, respect for national law, procedural fairness and non discrimination – which contribute to reducing transaction costs for business and increasing investor confidence in the Ukrainian jurisdiction. It was established that the legal environment of the European Union is based on unified and digitalised procedures of international legal assistance, which ensure electronic service of documents and the exchange of evidence between courts of the Member States. The study found that foreign jurisdictions demonstrate a high level of predictability and legal stability in matters of judicial control over international arbitration. It was revealed that European case law adheres to the concept of limited interference in the activities of arbitral tribunals, which helps preserve the autonomy of the arbitral process. In the Anglo-American model, a trend towards consistent enforcement of foreign arbitral awards, including those rendered in disputes involving foreign states, was confirmed, provided that procedural standards and public policy requirements are observed. The study showed that the institutions of judicial control, state immunity and recognition of arbitral awards in these legal systems function in a complementary manner, ensuring a balanced approach between the sovereign interests of the state and the needs of international business. The results obtained have practical significance for improving Ukrainian mechanisms of international legal assistance and for harmonising national legislation with European and Anglo-American standards