Food insecurity creates serious ethical, economic, and stability problems in all countries of the world, resulting in a need for its research. Each country seeks to ensure the highest degree of self-sufficiency in meeting the food needs by its own food production. However, the production of a sufficient quantity of food, and in particular its adequate structure, is not always fully realized. Therefore, ensuring food security has become an issue of primary strategic importance. Given that all the countries of the former Yugoslavia are relatively new countries undergoing a difficult period of transition, and that there are no local studies on food security, it remains to be examined how food- secure these countries are today and what factors affect their food security. The survey covered all countries of the former Yugoslavia: Republic of Serbia, Federation of Bosnia and Herzegovina, Republic of Montenegro, Republic of Croatia, Republic of Slovenia and Northern Macedonia. The survey data were taken from the FAOSTAT database, World Bank, as well as the national statistics of the countries of the former Yugoslavia, and hierarchical regression analysis was used. The results of the research showed that there is a statistically significant influence on the level of food security of all independent factors: general level of economic development, population growth, foreign trade, investments in agriculture. Of all the countries of the former Yugoslavia, Slovenia has emerged as the most nutritionally secure country, while the lowest level of food security has been observed in Bosnia and Herzegovina.