The 30-year period of experience with democracy in Slovakia has raised a lot of constitutional issues to be solved. The theme of unwritten constitutional law was not among those to which the greatest attention was paid. Nevertheless, it has become clear that the constitutional texts do not cover all the issues that constitutional practice raises and that also in the constitutional system of Slovakia there are elements that can be considered as constitutional customs. This fact is also proved by the growing interest of the Slovak theory in the issue of unwritten constitutional law in recent years. The aim of this paper is to identify unwritten elements in the constitutional practice of Slovakia, to analyse them and, on that basis, to evaluate their exact nature and force.