The international comparative evidence on the nexus between finance and growth is ambiguous, owing to the many difficulties in isolating finance, separating its growth effect from that of the other factors. To overcome this problem, we study the effects of financial development on growth from 1960 to 2010 in one country—Italy. Thus, we have the same political, legal and regulatory framework but also sharply differing development conditions between regions. After World War II, Italy achieved an “economic miracle” similar to what China and India are now experiencing, followed by a lengthy phase of decline. Accordingly, we can distinguish the effect of financial development on growth from other potential causal factors while also considering regions with sharply different economic conditions. Our results show that from 1960 to 1980, when the Italian “economic miracle” was still under way, finance played no significant role in favouring the surge in economic growth, which most likely depended on internal consumption. Between 1980 and 2010, by contrast, the great expansion of Italian financial markets and institutions did have a positive effect on regional economic performance, but overall growth rates were nevertheless low. Although our empirical evidence supports the view that finance is more important for growth in less highly developed regions, it also shows that financial development has not helped to overcome the Italian economic divide.