The article examines the theoretical and applied foundations of the assessment of financial and economic security in the system of financial monitoring of the enterprise's activity. It is emphasized that the financial monitoring of the enterprise's activity characterizes the functional mechanism of constant monitoring of the enterprise's financial indicators, which includes obtaining, systematization, and analysis of financial information in order to establish cause-and-effect relationships, based on the comparison of analytical data of the enterprise's functioning with normative ones. Monitoring of the financial activity of the enterprise must be carried out at various stages of financial management in order to make key managerial financial decisions. It is noted that in the economic literature there are various methods of assessing the level of financial and economic security of economic entities, which are based mainly on the ratio analysis of financial statements. Analyzing these methods, it is advisable not to allow an excessive number of coefficients, since, duplicating each other, they do not bring much benefit to the formation of a holistic picture of the level of financial and economic security. Monitoring of the effectiveness of the financial and economic security of the enterprise is based on methods of assessing the probability of bankruptcy. Based on the obtained results of the use of models for assessing the probability of bankruptcy, it was established that the investigated enterprise is not in danger of bankruptcy. However, there is a gradual decrease in estimated indicators, and if the company does not take measures to maintain financial and economic security in proper condition, it may enter the risk zone. Attention is focused on the fact that in order to diagnose crisis situations, the enterprise needs constant monitoring of factors that cause internal and external threats to financial and economic security. Measures that can be aimed at neutralizing the threat of a financial crisis are proposed. In general, the assessment of financial and economic security as a component of the system of financial monitoring of the enterprise's activity must be considered as an important tool for its sustainable development and successful functioning.