Recent research has demonstrated that national and subnational policymaking in advanced democracies tends to respond unequally to the policy preferences of different actors and groups in society. However, little is known about whether similar biases characterize supranational policymaking in the European Union (EU) and, if so, under which conditions EU policymaking responds unequally to the preferences of different types of stakeholders (which can be organized interests or the public at large). This paper explores these questions by analyzing an original data set of 43 legislative proposals for which the European Commission (EC) organized an open public consultation among stakeholders prior to the formulation of the respective proposal. The data set reports for each policy alternative included in one of the public consultation surveys (i) the level of support different stakeholder types expressed for the policy alternative and (ii) whether the policy alternative was included by the EC in their legislative proposal. The results of the analysis show whether and to what extent EC policymaking is unequally responsive to different stakeholders as well as the conditions under which unequal policy responsiveness may arise. These results are relevant to both researchers and practitioners since the EC has established one of the most comprehensive open public consultation regimes, with the aim to increase its input and output legitimacy by giving interested stakeholders greater opportunity to voice their preferences at relatively low cost in the policymaking process.