
In proceedings before the International Criminal Court, expert evidence is of particular procedural importance. The use of specialist expertise is essential given the high level of complexity of cases involving perpetrators accused of war crimes, crimes against humanity or genocide. The scale and scope of the evidence available to the Tribunal makes it necessary to use the special knowledge of experts covering a wide range of opinions. This study presents the most important rules regarding the procedural status of experts appearing before the ICC. In view of the full-scale aggression of the Russian Federation on the territory of Ukraine, which started on February 24, 2022, and the investigation initiated by the ICC on March 2, 2022, concerning war crimes, crimes against humanity or genocide allegedly committed on the territory of Ukraine, it was justified to point to the specificity of opinions in these international criminal proceedings.