Consultation is crucial to bring together stakeholders and public authorities by involving the former in decision-making. Moreover, it could be helpful in improving law and regulation, by providing public authorities with evidence and data on stakeholders’ positions. For these reasons, it is generally recognised that consultation can help improving the quality of rules and rebuilding public trust. But these are not necessarily the results and the tool can backfire. The paper claims that law and regulation effectiveness and public trust are not automatically related to consultation processes, but they need effective consultation. What makes consultation effective in involving relevant stakeholders, providing decision-makers with valuable and unbiased data, and thus improving public trust are the question the paper deals with.