Spain and Portugal have long been considered exceptions when it comes to the electoral success of radical right-wing parties in Europe. This scenario changed for both countries in 2019, with the extraordinary rise of Vox in Spain and the comparatively more modest election of one representative of Chega in Portugal. Their emergence – and the stark difference in the extents of their success – provides researchers with an ideal ‘edge-case’ and can be explained via a theoretical model that builds on and fuses previous explanatory models for radical right success. The Iberian cases demonstrate that radical right parties succeed when they (i) avoid the stigma of extremism, (ii) benefit from a gap in political supply on the right and (iii) cater to an unsatiated demand of voters on a salient sociocultural issue. While both countries had long been home to marginal far-right political forces, the stigma of extremism prevented them from being considered credible political alternatives. The appearance of new parties that emerged as a result of splits from the mainstream centre-right, in both cases reflecting a beleaguered political supply, gave the radical right an opportunity to avoid stigma, as we demonstrate through a news content analysis. However, whereas in Spain Vox could profit from both the Catalan independence challenge and the uptick in salience of immigration, which had previously been anomalously low in Iberia, Chega has not (yet) benefited from a similarly ripe political opportunity structure in Portugal.