摘要:In June 2003 the Czech voters had for the very first time a chance to vote in a referendum on the European Union membership. 77,3% of the voters supported the Czech membership in the EU, 22,7% of them were against. The turnout amounted to 55,2%, considering that The Law of Referendum, in contrast to for example Slovakia or Poland does not require the antiquation of 50% limit to accept the voting as valid. The referendum stopped the series of years´ lasting debate, whether the membership of the Czech Republic in the European Union would be favourable or not. This article compares the influence of political parties on referendum outcome and analyses some socio-demographical data, which could af ect voters´ decisions.