At the end of 2019, the National Assembly adopted the National Security Strategy of the Republic of Serbia. This is the second document of this kind since Serbia became an independent state again, because the first document was adopted in 2009. This paper is an attempt at a comparative analysis of the mentioned documents that are of vital importance in the field of national security. In that sense, the paper first analyzes the concepts and structure of documents, then the basic attitudes and determinations and, most importantly, the the content of extremely important national documents. The authors' conclusion is that the new National Security Strategy from 2019 is qualitatively different as compared to the previous document, as well as that it has identified some important issues that require a broader and deeper theoretical elaboration.