The article reveals the essence of the organizational and legal basis of the activity of pretrial investigation bodies. The scientific conclusions regarding the organizational and legal basis of the activity of pre-trial investigation bodies were analyzed. The main areas of research of scientists who at various stages were engaged in the study of problems related to the general characteristics of the organizational and legal foundations of pre-trial investigation bodies were studied. It is substantiated that the organizational and legal principles of the activities of pretrial investigation bodies determine the dynamics of the implementation of the goals of these bodies through a system of actions, operations that change, develop and improve, thanks to which the goals and the tasks and functions of the pretrial investigation bodies are manifested. The organizational and legal principles of the activity of pre-trial investigation bodies are characterized by continuity, cyclicality, carried out simultaneously in different directions. The analysis of the content of the organizational side of the activity of pre-trial investigation bodies shows that the organizational and legal basis of the activity of pre-trial investigation bodies is the activity of subjects united in a certain organizational structure (pre-trial investigation bodies and their employees), which is aimed at solving practical problems and achieving the goals set before the system of pre-trial investigation bodies by implementing the necessary types of activities based on the defined principles of administration, with the use of appropriate administration methods. It is emphasized that the study of the organizational and legal foundations of the activity of pretrial investigation bodies allows to determine the optimal ways of development and modernization of the law enforcement sphere to European standards. Attention is focused on the fact that in the current military state of the state, the issues of ensuring the proper organization of the activities of pre-trial investigation bodies, the implementation of the state security policy, the creation of legal and organizational mechanisms of public-private partnership regarding the above-mentioned issue by stimulating and involving the nonstate sector in solving law enforcement problems, regulating at the legislative level all forms of public-private partnership in the law enforcement sphere. Key words: investigators of the National Police, security agencies, the State Bureau of Investigation, detectives of the Bureau of Economic Security.