As the introduction to this special issue highlights, the Great Recession, along with the more recent phenomenon such as the refugees’ crisis and the Brexit referendum, has contributed to the success and strengthening of populist Eurosceptic parties across European party systems. The loss of legitimacy of governments and European institutions has opened a window of opportunity for parties expressing anti-establishment positions and populist orientations and criticizing the political-economic arrangements prevailing in Europe. Our study focuses on the rise of a specific left-wing populist Euroscepticism linked with the impact of the Great Recession and austerity measures in Portugal and Spain and the party system transformations. Thus, economic issues, bailouts, and, above all, anti-austerity measures were the main driving forces behind the transformations of Iberian party systems. The increase in populist reactions in both countries after the economic crisis and the implementation of austerity had to do with the transformation of the radical left emphasizing distributive issues in Eurosceptic populist directions. Finally, the analysis shows the distinctiveness of the populist Euroscepticism of the new challenger, Podemos, which illustrates the opportunities afforded with the economic crisis for the rise of new challenger parties exhibiting the contemporary link between populism and Euroscepticism in the radical left.