The article may be of interest to representatives of the audit service, members of internal control and managers of all levels within the system of the Ministry of Defense of Ukraine and the Armed Forces of Ukraine. In the course of the study, a partial analysis of the governing documents regulating the organization and functioning of internal audit and internal control systems in the defense department is conducted. The relationship between these systems is determined. It has been established that internal audit is an element of the domestic system of state internal financial control, which is considered as a three-level model. The analysis carried out in the article proves that the audit does not participate in making managerial decisions regarding the management of financial, material and other resources, and is not responsible for internal control, but carries out an assessment of the effectiveness of the functioning of internal control systems introduced by the heads of organizations. The article emphasizes the importance of using the "Three Line of Defense" model in the Defense Department. An independent function of internal audit through a risk-oriented approach to its implementation should provide sufficient assurance (guarantee) for senior management. In the course of the research, not only the analysis of regulatory acts regulating its activities, but also the analysis of the performance indicators of the internal audit units. The high efficiency and effectiveness of the internal audit units is high. The article analyzes the approaches to the organization and functioning of internal control in the defense department. The main elements of internal control and its participants are determined. The absence of internal control of the relevant competencies, the ability to understand the processes that could lead to a violation of the functioning of the system of the entity of internal control that the representatives of the audit service have. A decision has been made regarding the development of certain recommendations to participants in internal control in the form of the development of a certain system of indicators that can signal and prevent the failure of the functioning of the system for the management of financial, material and other resources.