The article analyses problems with which the Republic of Croatia, as a country in transition, has to contend during war crimes proceedings. A major characteristic of the recent wars waged on the territory of the former Yugoslavia is that war crimes were committed, though on a different scale, by all parties involved, irrespective of the political and other motives that prompted them to engage in armed conflict. Political unwillingness is the principal reason why national courts, including those in the Republic of Croatia, did not prosecute war crimes in accordance with internationally acceptable standards. The international community responded by setting up the International Criminal Tribunal for the former Yugoslavia (ICTY), the main objectives of which are to establish justice, render justice to victims and determine the historical truth. Implicitly, despite political and other opposition to its work, the ICTY is helping to define legal and ethical standards appropriate for a democratic society in the countries established on the territory of the former Yugoslavia. This is particularly important for the reason that all these countries aspire to membership of the European Union. The work of the ICTY, as well as proceedings before domestic courts, is therefore an important legal, political and moral catalyst on their way towards accession to the European Union. This is fully confirmed by the example of the Republic of Croatia.