The main goal of the article is to establish how a small country, Slovenia, promoted its national interests when it held the Presidency of the Council of the EU, how this experience fits into the theory of small states and what lessons can be drawn for other small states. Based on a questionnaire administered to key Slovenian actors in the presidency, the analysis confirmed some of the theoretical expectations and revealed certain disparities. Our analysis confirms theoretical predictions that a member state can push through its national interests more easily during its presidency because it possesses certain powers that enable it to set the agenda, which is the most effective way of realising national interests. Especially true in the case of small state presidencies, advocating national interests can also be facilitated by a smaller range of priorities and a greater level of coincidence with the interests of other key actors. We revealed that, besides the country’s size, other factors also limited its ability to fulfil its national interests. In addition to a weak ability for coalition building and lobbying, the two main factors of constraint were the lack of soft knowledge among Slovenian officials and weak coordination among policy agents.