There is ongoing debate as to whether polarization increases or decreases the impact of voters’ perceptions of parties’ competence and position on their vote choices. Polarization should lower the impact of competence-based voting and increase the impact of positions because in polarized systems parties’ positions are clearly differentiated. Yet, the findings on the moderating role of polarization have yielded mixed results. This study presents new comparative evidence from the 2019 EP elections and contributes in three ways. First, our theoretical framework incorporates both polarization of parties and voters to better understand the way in which polarization affects the importance of positions and competence on the vote. In terms of the party offer, we examine the extent to which polarization of parties’ positions on an issue affects voters’ propensity to engage in competence and spatial voting. We also propose that voters with polarized (eccentric) positions on an issue are more likely to engage in spatial voting compared to voters with moderate (centric) positions. Second, we examine the interplay between voter and party polarization. Our key expectation is that party system polarization increases the difference between moderate and polarized voters: voters with strong stances on an issue will be more inclined to engage in spatial voting compared to moderate voters, but their ability to do so is further enhanced when the party system offers more divergent choices. Third, we present rich evidence that allows us to test our expectations in 10 EU member states and for four issues.