This article examines the extent to which differences in educational attainment produce unequal political representation. The lowest educated have almost disappeared from political office-holding, and some scholars argue that, subsequently, their preferences are underrepresented. However, the substantive underrepresentation of the least educated has yet to be empirically established. Based on data of the Dutch Parliamentary Election Studies 1994–2010, this study finds that the preferences of least educated citizens are worse represented than the preferences of higher educated citizens, indicating that political representation is biased towards the highest educated. This unequal representation is found on moral, socio-economic and cultural issues. However, the underrepresentation of the lowest educated is not continually present. This study shows that successful right-wing populist parties enhanced the substantive representation of the least educated in certain policy areas.