This study provides a comparative analysis of preliminary proceedings within the criminal justice systems of the Republic of Serbia, Germany, and Italy. Preliminary proceedings, as the initial phase in the criminal process, play a crucial role in ensuring fair trials and the proper administration of justice. By examining the legal frameworks, procedural practices, and roles of key actors in each jurisdiction, this research highlights the similarities and differences in how these countries approach the preliminary stage of criminal cases. The study reveals that while all three systems share common objectives—such as safeguarding the rights of the accused and ensuring thorough investigations—there are significant variations in procedural mechanisms, the involvement of judicial authorities, and the rights afforded to defendants. These differences reflect the distinct legal traditions and cultural contexts of each country. The findings of this study contribute to a deeper understanding of European criminal procedure and offer insights for potential harmonization efforts within the European Union.