Despite the joint history of Montenegro and Slovenia as republics of the former Yugoslavia, the development of the interest groups system has been different in these countries. While in Slovenia, these groups started to develop from the 19th century, in Montenegro the interest groups system was almost non-existent in the pre-socialist period with only a few participative elements, such as the use of tribal assemblies. Socialism did not support associational life, since most of the organizations that were founded at the time were under some form of government control. As a consequence, the interest groups system in Slovenia shrank during socialist rule, while in Montenegro it remained at the same level. During the 1980s and after the collapse of the socialist regime the interest group system in Montenegro finally starts to develop, being heavily influenced by international donor and assistance programmes, while in Slovenia the system had a new opportunity to flourish. In this article we are in particularly interested in how the interest group system contributes to the quality of democracy. Although Montenegrin interest groups have been a tool of influence and democratisation primarily on behalf of the international community, their internal democracy is less sophisticated than is the case in Slovenia. The results show that the origin of the interest groups system and the distinct histories of the specific political cultures seem to be embedded in the functioning of contemporary interest groups. This in turn, determines the strength or weakness of these groups in facing the challenges of de-democratisation.