Introduction. Relevance of the research topic. Criminal proceedings are generally based on public law, which involves the participation of a prosecutor in criminal cases, who performs two main functions: criminal prosecution and supervision of the procedural activities of the preliminary investigation bodies. In cases of private prosecution, however, taking into account the specifics of initiating criminal prosecution, the lack of stages of initiation of criminal proceedings and preliminary investigation and the collection of the bulk of evidence by a private prosecutor, the Prosecutor cannot perform the same functions as in cases referred to public prosecution. Problem statement. Science did not use to pay much attention to the powers of the Prosecutor for criminal cases of private prosecution. Even in scientific works directly dealing with the issue, only concise norms of the criminal procedure law, without their detailed disclosure and specification, were mainly reproduced. Goals and methods. The aim of the research is to develop an optimal theoretical model of the prosecutor’s participation in criminal cases of private prosecution and to formulate a list of their powers. The work is based on the dialectical and materialistic method, which involves a comprehensive study of phenomena, their interactions being taken into account. Such methods as formal and legal, analysis and synthesis, deduction and induction have also been used. Results and key conclusions. The author makes suggestions about possible theoretical models of the Prosecutor’s participation in the category of cases under consideration, points at their defects and, as a result, suggests his own conceptual model. Attention is drawn to the fact that the attorney cannot go over to the side of the prosecution and should not be granted rights attributed exclusively to the private Prosecutor: to formulate a charge, to define people to be brought to justice, to petition for reconciliation with the accused. The Prosecutor in the cases of private prosecution procedure should preserve neutrality. At the same time, their participation is intended to make up for the characteristic features of the victim, which make it difficult for the latter to defend their right for justice and to be protected from crime. The paper formulates procedural rights the Prosecutor in a private prosecution case should be provided with and gives reasons for the Prosecutor’s necessity to give an opinion on the case, disclosed to the court and the parties at the end of the judicial investigation. It is stated, that the Prosecutor for private prosecution performs functions that are neither criminal prosecution nor supervision of the investigation bodies. They exercise supervision over the legality of the actions of the participants in criminal proceedings on behalf of the defense and prosecution in order to ensure the validity of the decision.