The aim of exercising the role of international courts takes the form of a judicial act. Depending on the variety and of their content international judicial acts occupies an important place in the system of the sources of international law, thus contributing, and sometimes even through them, carrying out important functions of international law to which we refer below. Especially, through its judicial act, the tribunal carries out the competence with which it has been invested. For these reasons, we propose the following functions which are exercised by the judicial act in the international law system. These functions were ordered depending on the powers vested on the judicial act, the nature of the judicial act, the impact on bilateral or multilateral relations and the interdependence of the proper functions: application of public international law, determination of international law rules, interpretation of rules Public International Law, identification of gaps in the field of Public International Law. The functions that meets the international judicial act, specific to the particular nature of the established jurisdiction, it implicitly contributes to the achievement of the most important objectives of Public International Law, playing a decisive role: the maintenance of international peace and security; the prevention and prosecution of international crimes and the protection of human rights and fundamental freedoms. The identification of gaps, uncertainties, and other contradictions of legal settlement in the process of solving an international dispute which has been referred to an international court, providing advisory opinions, the analysis of the factual and legal situations, has a political influence and, no doubt, a legal one on the international order. It provides opportunities of strengthening the legal foundation of the relations between the litigious states, regional group or a broader set of states, because it directly reflects the need for a regulated legal behaviour. These, stimulates the codification, the progressive development of distinct elements of international law, and, as a mutual influence, improve in the perspective the judicial functions of the international act.