The purpose of this study is to consider the phenomenon of ‘capital flight’ as a threat to the economic security of the country. This goal is achieved using general scientific methods, including analysis and synthesis, induction and deduction, abstraction, systematisation, and comparison. The study highlights the differences between the concepts of ‘capital outflow’ and ‘capital flight’, assesses the scale of capital flight and outflow, analyses the causes of these phenomena, and explicates the goals of capital flight. One of the causes of capital flight, namely tax evasion, is specified. The findings underscore the main directions of the impact of capital flight on the economic security of the country, and key measures to combat capital flight are proposed.