The degree of party polarization is a significant analytical measure contributing to our understanding of the party system development and it’s dynamic in time. It influences the government formation and indirectly also its stability. Moreover, the party polarization affects electoral choice and thus the voter decision-making process. Despite these it has been wrongfully neglected in the Czech political science literature so far. The aim of this paper is to fill this gap and present empirically backed data on the intensity and change of the party polarization in the Czech Republic. The analysis is based on the data sets of CVVM which monthly records the voter self-placement on the left-right scale in the long term. By analysing these data and using Dalton’s index of party system polarization it is proved that party polarization in the Czech Republic has generally increased since 1993 and that it was usually higher during General election campaign. Within the period under review (1993-2013) the polarization index reached its lowest value in 2001, while the highest value was found in June 2010., Eva Lebedová., and Obsahuje seznam literatury