It is often too easy to forget just how important the preliminary reference procedure is for the functionality of European Union law. For the Court of Justice, there are both formal and informal means of judicial dialogue. This article focuses on the formal means of dialogue through the preliminary reference procedure that is available to all national courts throughout the Union. This contribution underlines how critical the system of preliminary references has been for both Union law, and national law, ensuring legal certainty and conformity across a diverse range of legal cultures. Accordingly, it reflects on the true value the preliminary reference system, and highlights its continued importance for the development of both national and Union law.