The concept of energy security has a multidimensional character because dependence on energy sources extends beyond the field of energy and is reflected in the economic, military, political, social, and environmental sectors. Such an integrated approach is crucial for the appropriate positioning and strengthening of the concept of energy security within the framework of national security. This paper analyses the answers to the research question: Is there an elaborate concept of energy security in the Republic of Croatia from the perspective of national security? Additionally, this paper analyses whether and to what extent the “status” of energy security has changed in the concept of national security of the Republic of Croatia. The analysis in this paper is based on longitudinal monitoring of the development of the concept of the energy security framework in the period from the adoption of the first National Security Strategy of the Republic of Croatia until today, based on the example of national security strategies adopted so far in 2002 and 2017. Since the focus of interest is positioning energy security within the framework of national security of the Republic of Croatia, this research aims to contribute to the understanding of the need for further development and strengthening of the concept of energy security within the framework of national security and to stimulate further research with the aim of defining activities and measures to increase the resilience of the Republic of Croatia to di