After the First Republic, a growing instability has been affecting Italian politics at different levels. Most of the literature has focused on the transformation of Italian political and party systems from a national point of view; however, the analysis of regional level could be used to better understand the trajectories of instability in Italy. The paper aims to contribute to the existing literature on instability and regional politics. An analysis of national, regional and European electoral data in three different periods (First Republic, bipolar Second Republic, tripolar Second Republic) will be provided in order to assess the degree of instability of each region over time. Regional majorities are confirmed to have become increasingly unsure about their own re-election even in those territories being historically considered as parties’ strongholds at subnational level; the results of the analysis show that instability affects all regional political systems even more after the appearance of a third pole (the Movimento 5 Stelle – M5S) in 2013, with the only exception of the Veneto region.