The impact of the European Convention on Human Rights on national legal orders is not limited to the enhancement of the protection of individuals’ rights, but implies broader transformations in the constitutional structure of states. This paper investigates the on-going re-shaping of domestic systems of sources of law entailed by the implementation of the concepts of “law” and “legislation” as elaborated by the European Court of Human Rights. With particular reference to the Italian case, the focus is on one of the doctrines that dominated scholarly literature in the last centuries in continental Europe – so-called Gesetzesvorbehalt – which seems to be facing a serious crisis with these latest developments.