This essay summarizes the development of the autonomy principle in the theory and practice of Italian regionalism. It aims at demonstrating how difficult it is to find a theoretical model suitable to present-day Italy. Indeed, in Italy regionalism has always been pursued as a way to fulfil goals different from autonomy; so that it is difficult even to recognize it in the effective structure of relationships between State and regions. As the study points out, the real reasons behind regionalism in Italy are historical and mainly political, and can be discovered by tracing the steps of the regionalist movement: from the “Risorgimento” (“Resurgence”, the long struggle for Italian unification, 1815-1870), to the Constituent Assembly; from the long period of failure in the realization of regions (1948-1970), to the constitutional reforms of 1999 and 2001. The current situation can be described as that of a “confused” regional law: a faded and distorted image of the project hastily outlined by modifying the “Titolo V” (Fifth Title of the Second Part) of the Constitution. A broad cultural change in Italian political class would be necessary in order to promote truly the principle of regional autonomy. Otherwise, regionalism (or federalism, as it is confusedly called today) will remain shapeless – without a model – for a long time yet.