As politics become more polarised and the spread of misinformation more prevalent, one might ask whether election outcomes in proportional elections are becoming more contested. The media have an important responsibility with respect to the electoral integrity of democratic elections. The purpose of this paper, therefore, is to shed light on the extent to which media framing of election outcomes in terms of legitimising or challenging them has consequences for the degree to which voters accept election outcomes. We pre-registered several hypotheses that concern the direct effect of media framing on election outcome acceptance, in such way that legitimising (challenging) frames will have positive (negative) effects. We also expect a mediating effect via the degree to which voters consider certain parties winner or losers of the preceding election, which affect the respective positive and negative effects on election outcome acceptance. Furthermore, we expect that perceived threats of misinformation and perceived electoral integrity will moderate the direct and indirect effects, be they positive or negative. To test our hypotheses, we link data on media coverage following the 2024 European Parliament elections to a three-wave panel survey conducted before and after the elections in three countries, namely the Netherlands, Germany, and Poland. The main linking variable is media use, which we employ to weigh the extent to which voters were exposed to legitimising or challenging framing right after the elections. Our results have important implications for European politics, political contestation, and democratic legitimacy of elections.