A threat is a factor that causes the likely destruction of the system and leads to crisis events. A security threat is a set of conditions and factors that endanger the vital economic interests of a person, society and the state. Internal threats to the monetary system make it impossible to ensure the necessary level of economic growth, negatively affect the trade, internal and foreign economic activities of Ukraine, contribute to the emergence of obstacles to improving the budget, tax, insurance and several other financial systems of Ukraine. The successful solution of this problem directly affects the monetary, economic, social and political stability of Ukraine. Therefore, the definition and solution of internal threats to the monetary system and the financial and economic security of the state are one of the pressing problems of today. The article classified, examined and analyzed internal threats to the monetary security of the state, their impact on the financial and economic security of Ukraine. To better understand the problem and detail the threats, the author grouped the threats of the monetary system by the directions (spheres) of their manifestation. The selected groups of monetary threats are considered and analyzed in more detail, since they lead to a violation of the economic balance of security in the state and require the development of a system for managing them and countering their negative impact on the economic system or localizing their actions. The theoretical aspects of the financial and economic security of the state have been studied by many authors. Noteworthy are the scientific works of such well-known economists as: Abalkin L.I., Alikperov I.M., Baranovsky O.I., Bogachev V.I., Bogdanov I.Y., Burtsev V.V., Vershinin V.M., Vozhenikov A.V., Delyagin M.G., Yermoshenko N.N., Echmakov S.M., Kozyrin A.N., Kolosov A.V., Kuklin A.A., Popov E.V., Senchagov V.K., Fokina N.P., Shnipko O.S., Lebid O.V., Garkusha V.O. and others. However, the emergence of new internal threats to the monetary system and the uncertainty of the essence of financial and economic security require additional research. The purpose of this work is the need to classify and justify rational and more effective mechanisms to counter internal threats to the monetary system of the state. Having studied the totality of monetary threats and their impact on the economic security of the state, we came to the following conclusions: monetary threats are created under the influence of external national and supranational threats (factors) that actually activate them; it is advisable to divide monetary threats into four groups: institutional, monetary, banking, investment - in the place (area) of the threat; the activity or inactive state of a threat can be determined by analysing the dynamics of the indicators that characterize it; the study showed that each of the identified threat groups has active threats that require the development of measures to minimize or counter them; today, the most active threats lie in the institutional environment of the monetary system, since most of them are subjective in nature and depend on from the professionalism of officials, their qualifications, the desire to change the situation, etc.