Introduction. With the adoption of the Criminal Procedure Code of the Russian Federation, the legal regulation of the final stage of the preliminary investigation was significantly changed. As the legislator believed, for the better. At the same time, not all the provisions can be recognized as theoretically and empirically justified. The issue of ensuring the rights and participants freedoms in criminal proceedings at this stage remains problematic today.In the article, the author conducts a comparative analysis of the forms of completion of the preliminary investigation in the Russian Federation and some CIS countries, highlighting the positive experience of both foreign and domestic legislation regulating certain aspects of the investigator procedural activities, head of the investigative body, and the prosecutor at the final stage of the investigation.Methods.The author compares the normative regulation of the main forms of the preliminary investigation completion in the form of an investigation: investigation completion with the preparation of an indictment and transfer of the criminal case to the prosecutor for referral to court and termination of the criminal case at the stage of preliminary investigation in Russia, Belarus, Azerbaijan, and Kazakhstan.The author also analyzes and compares the functioning of such legal institutions as departmental procedural control and prosecutorial supervision at the final stage of the preliminary investigation.Results.Having analyzed the criminal procedure legislation of the Russian Federation, Belarus, Azerbaijan and Kazakhstan and having conducted a comparative analysis of the two main forms of the completion of the preliminary investigation various aspects, the author believes it is possible to discuss the issue of enshrining in the Code of Criminal Procedure of the Russian Federation a number of provisions similar to those existing in the Code of Criminal Procedure of the above-mentioned foreign countries.