In the last decade, there have been numerous studies on the rise, characteristics, and consequences of the emergence of populist parties in Western liberal democracies. However, most analyses of European populist parties have focused on the right-wing populist parties. Although some scholars have made valuable efforts to understand left-wing populism in Europe, these studies have paid attention to their ideological-organizational idiosyncrasies or the characteristics of their electoral bases. This paper aims to fill the gap in the economic and political contexts in which Radical Left Populist Parties have achieved significant electoral results putting into practice a fsQCA analysis and examining their uneven electoral performance in Europe. Following some previous work applying QCA techniques, this paper tests the theory on the importance of economic and political factors. Findings indicate that the electoral performance of radical left populism cannot be explained in a univocal way, highlighting the crucial role of equifinality in understanding this political phenomenon. [ABSTRACT FROM AUTHOR]