The focus of this book is on the - so far hesitant - diffusion of non-marital cohabitation in Italy. During recent decades, cohabitation has spread rapidly in most European countries. However, in the Mediterranean context, and in Italy especially, we observe merely a slight diffusion of this new type of living arrangement. The reasons are multi-layered but can nevertheless be attributed in the main to the interaction between the prevailing cultural system and the peculiarities of the Italian welfare state. Combining quantitative and qualitative research methods, the study aims to address two different issues. The first focuses on the role played by the social background in women's transition to informal cohabitation in Italy. The second issue concerns the motivations, perceptions, and expectations young women have when deciding for or against cohabitation. Here, we consider regional differences in particular and focus on the cities of Bologna and Cagliari. The findings show, among others, that we find a special kind of cohabitation in Italy that differs considerably from cohabitation in other European countries.