Although sharing institutions for over seventy years, and transition pathways from communism, the two successor states of the former Czechoslovakia have faced distinct challenges in state-building and divergent economic fortunes. The aim of this paper is to investigate the extent to which these differing social economic problems have influenced the ideological bases of party politics and mass electoral behaviour in the two societies. Using data from national samples of the population of each country conducted in the spring of 1994, our analysis points to the existence of distinct issue cleavages dominating party competition in the two states: in the Czech Republic, partisanship relates mainly to issues of distribution and attitudes towards the West; in Slovakia, by contrast, these issues are only secondarily important in shaping voters' choice of party, while the main focus concerns the ethnic rights of Hungarians. The distinctive nature of the issue bases to politics in the two countries suggests one reason for the greater degree of political conflict evident in Slovak politics since the split and, more generally, provides evidence of the role of social conditions in shaping new political systems.