Considered as a manifestation of the current crisis of political parties in established democracies, levels of split-ticket voting have been increasing in these countries in the last decades. By split-ticket voting I refer to the phenomenon in which citizens vote for two different parties in concurrent elections. However, what would it happen if elections across arenas take place at different points in time? Focusing on Spain, I aim to understand the determinants of the so-called dual voting, that is, the electoral behaviour of citizens that split their vote in non-concurrent national and regional elections in this country. In order to investigate this phenomenon, I will analyse survey data between 1998 and 2012. The results suggest that people engage in dual voting because of a myriad of factors that include ideological and national identification, retrospective and prospective evaluations of the regional and national incumbents, and the differences in the permissiveness of the electoral system across arenas. Above all, the evaluation of candidates appears as the most important variable to explain the variation in this phenomenon.