Despite the increased use of stakeholder consultations, little is known about their impact on the legislative process. We examine how consultation of external actors during policy preparation affects decision-making duration and efficiency. We test our predictions on EU legislative decision-making and we find that although stakeholder consultations in policy preparation may increase the democratic legitimacy of decision-making, they result in efficiency losses in the subsequent legislative processes. Hence, rather than smoothing the way for quick legislative reconciliation, consultations increase the transaction costs of subsequent bargaining by prolonging the time needed to form the necessary coalitions and reach legislative deals. However, despite the proliferation of different tools for involving external actors, we find no differences in legislative speed between open and restricted consultations.