The goal of this work is to better understand the institutional changes in the educational systems of the Czech Republic, Hungary, Poland and Slovakia. We demonstrate that the educational reforms implemented during the transformation introduced very different institutional arrangements in the four countries, despite the fact that their systems shared many common characteristics at the beginning of the 1990s. Differences between the national approaches to educational reforms are particularly reflected in the modes of education decentralisation, the level of school autonomy, accountability and funding mechanisms. We believe that different institutional arrangements may have contributed to the divergent achievements of the Czech Republic, Slovakia, Hungary and Poland in the PISA programme.