Two new states, the Czech Republic and Slovakia, came into existence upon the division of one country in 1993, and these states implemented a new tax system in the same year. The tax system was legalized in 1992 and that is why the taxes of the two states were originally almost identical. However, many amendments of tax laws took place as soon as in 1993 and gradually, in spite of the tax harmonization process of the EU, the gap between the tax systems of the Czech Republic and Slovakia has widened. The paper aims at analyzing the growing differences in tax revenues (or in the tax burden of the two economies) and at finding out which taxes contribute the most to the growing differences. The method of breaking down the difference between the quotas to items - individual taxes - according to the classification used by Eurostat has been selected.