Introduction. Studying the history of criminal procedure institutions allows to fully comprehend their essence, as well as to comprehend the logic of the legislator who formulated a certain rule of law in one form or another. In this regard, the analysis of archival criminal cases is of particular scientific interest, the study of which contributes to the objective study of the documentation of the pre-trial criminal procedural activity of the criminal prosecution bodies of the Byelorussian Soviet Socialist Republic (BSSR) of the mid-twentieth century and its further evolution. The purpose of this article is to study the documentation of the pre-trial criminal procedural activities of the criminal prosecution bodies of the BSSR of the mid-twentieth century. Methods. The methodological basis of the research is a combination of general scientific (dialectical, deduction, induction, analysis, synthesis, etc.) and private-scientific methods (legal-technical, comparativelegal, empirical, etc.). Results. In the course of the study, the conclusion was formulated that the pre-trial proceedings of the BSSR in the middle of the mid-twentieth century were to some extent influenced by pre-revolutionary legislation and law enforcement practice, which was reflected both in the provisions of the Criminal Procedure Code of the BSSR and in the activities of the Soviet criminal prosecution bodies. On the other hand, the systematic deviations of investigators and interrogators from the archaic requirements of the Soviet criminal procedure law subsequently led to the transformation of such actions into the norms of the law of the Criminal Procedure Code of the BSSR of 1961 and the Criminal Procedure Code of the Republic of Belarus. In addition, attention is drawn to the preservation of the rules of registration of certain procedural documents (known at least since the beginning of the twentieth century) in the modern activities of the Belarusian criminal prosecution bodies. In the process of writing the article, the procedure for conducting face-to-face interrogation and the presentation for identification at the stage of development of the criminal process, when they such have not yet been considered by the legislator as investigative actions, is considered.