The legitimacy of the electoral process is crucial for the consolidation of democracy. We here focus on individual perceptions of electoral integrity (IPEI) and seek to understand what factors can explain different degrees of IPEI. In particular, we use the sixth wave of the World Values Survey (2010–14) to examine how antiauthoritarian values affect individuals' directional bias, driven by political party support, in evaluating electoral integrity. The results show that IPEI do depend on an interaction of political party support and the strength of antiauthoritarian values. However, the addition of the latter does not lead to a convergence of integrity evaluations among winners and losers, as may be expected under the assumption that antiauthoritarian values drive voters to more carefully monitor and evaluate the electoral process. Instead, it leads to greater polarization between electoral winners and losers. We explain the result with reference to the motivated reasoning literature on biased information processing: While antiauthoritarian convictions lead people to obtain more information on the electoral process, their political leanings bias their reading of this information, which in effect leads to stronger polarization in perceptions.