Although the literature on the determinants of successful democratic transition is substantial, it has greatly overlooked the impact of authoritarianism on the formation party systems in new democracies. How does the legacy of authoritarian rule affects the evolution of party systems in these countries? We develop a theory that encompasses authoritarian regimes of the post-WWII period located in Southern, Post-Communist Europe and Latin America. We build our expectations on two premises: that authoritarian regimes are not ideologically neutral and that after democratic transition both citizens and political elites are critical to the previous regime. This combined logic suggests that political parties in new democracies attempt to move away from the ideology of the dictator, placing themselves on the opposite side of the ideological spectrum. We show that in both left and right-wing regimes there are asymmetric levels of party system fragmentation, with fewer parties located in the dictator’s ideological side. This positioning tends to converge with time as party systems become consolidated.