The article deals with the importance of the Italian state intervention in the 20th century in selected sectors of the economy (in regional terms) on the subsequent socio-economic situation of the regions. Due to the observed today very large differentiation of the regions, the question is whether and to what extent the central policy of the Italian state of the post-unification period influenced the disproportions occurring today? The article consists of three main parts: the first outlines the contemporary socio-economic differentiation of the regions, the second presents the economic condition of the regions after the unification of the country, and the position of the state, and the measures it has taken, including repair programs used to improve the socio-economic conditions of the regions, the third part assesses the relevance and legitimacy of the implementation of these measures in the context of the current situation of the country. The aim of the article is to indicate the importance of the role of state policy, and the decisions taken in the past on the contemporary economic condition of Italian regions. Thus, the author attempts to explain the permanent, and in some areas still deepening, differences in the socio-economic development of Italian regions.