n the last decade, several studies have developed and updated different rankings of countries, regions and cities in order to describe and measure their performance in a varied urban aspects, including economic and social ones. In particular, as the number of composite indexes developed worldwide is growing, in the last years, one of the topics that has mostly attracted the interest of academia, and even beyond, is that of the Smart City. In this context, this chapter aims at the development of a composite indicator to measure and compare the inclination to smartness of twelve Italian metropolitan cities, where several initiatives have been carried out to improve their level of smartness. The index has been constructed based on six main dim...