Interest of international law scholars into an empirical research has increased in the last decade. This paper is an example of one such research. The author has empirically analyzed positions on the use of force against the Federal Republic of Yugoslavia to test hypothesis about the operational role of international law in the work of the UN Security Council: whether it was used in the formation of positions, in the assessment of the situation, and in proposing its solution. Introductory part of the paper presented basic features and development of empirical research of international law. It is followed by the review of theoretical assumptions on the role of international law. Next sections of the paper presented hypothetical framework, methods and results of this empirical research. Finally, the author made concluding remarks on research findings, as well as emphasized necessity to develop practical knowledge on empirical research of international law and to open a discussion on the potential and limits of its application.