The purpose of this work is to focus on the issues relating on one side tothe relation between the preliminary references and the human rightsprotection and, on the other side, to the use that Constitutional Courtshave made of it and on how this process can foster the effectiveness ofhuman rights protection in Europe. After having described the evolutionof the preliminary ruling‟s instrument - showing how it has become oneof the most useful tools to implement the European normativeintegrationthere will be highlighted some problematic aspectsconcerning the possible questions that can be addressed to theEuropean Court of Justice (ECJ), the margin of discretion of nationalcourts, and the right/obligation to refer a question for preliminaryruling. The third part of the work will address to the difficulties posed bythe possible (for a long time denied) dialogue between the ECJ andnational Constitutional Courts. While, in the final part of this work therewill be highlighted some critical points and reflections on some newperspectives connected, on one side, to the EU accession system to theECHR and, on the other, to the approval of Protocol n. 16, added to theECHR.