Abstract Cohabitation has been spreading in the population during the last thirty years, and this is one of the most striking aspects of wider social changes that have taken place throughout the industrialized world. However, this change did not take place uniformly across Europe. The purpose of this paper is to contribute to the current debate around the compatibility of cohabitation experiences with the Italian cultural context. Using an individual-level diffusion approach we obtain results that are consistent with the crucial role that family ties play in the choice of cohabitation in place of (or before) marriage. 1. Introduction Cohabitation has been spreading in industrial societies during the last thirty years, and this is one of the most striking aspects of general social changes that have taken place throughout these countries. The sudden gain in the popularity of cohabitation at the beginning of the 1970s as an informal way of starting a union can be explained by several factors. Cultural elements, such as rising individualism and secularism (Lesthaeghe and van de Kaa 1986), as well as economic aspects, such as changes brought by industrialization, changes in gender roles, and rising female labor-market participation, may have contributed to its increase (for a review, see Smock 2000). At the same time, the sexual revolution helped in removing the stigma surrounding premarital sex (Bumpass 1990). However, this change did not take place uniformly across Europe, one large exception being the Southern European countries. In the mid-1990s, about one in three women aged 25-29 in Sweden and Denmark was cohabiting; this compares to more than one woman in four in France, about one woman in six in Germany and the Netherlands, and less than one woman in 20 in Italy (Kiernan 1999). Demographers disagree on whether the country differences in the prevalence of cohabitation are likely to disappear over time or whether they will persist, as there are fundamental structural and cultural differences between the societies (Bernhardt 2004). Recent results from an analysis on the adoption of cohabitation among young Italian and German women (Nazio and Blossfeld 2003) seem to support researchers who do not see the differences disappearing over time, claiming that the diffusion of cohabitation among broad groups of the population in Italy is blocked. This differs from the empirical evidence presented in other recent studies (Rosina 2002, Rosina and Billari 2003, Rosina et al. 2003, Barbagli 1997, Barbagli et al. 2003, Rosina and Micheli 2006). They show that cohabitation starts to spread also in Italy and they argue that mechanisms related to the relationship between generations - and specifically between Italian parents and their children - are at the basis of the adoption or rejection of new behaviors (Rosina and Fraboni 2004). The purpose of this paper is to contribute to the current debate around the compatibility of cohabitation experiences with the Italian cultural context. We show that in Italy, this relationship is not influenced solely by the characteristics of the country's young adults but also by some of their parents' characteristics. The strong ties between parents and children and a welfare state that provides very limited direct help to youth are at the basis of the relatively scarce diffusion of non-marital cohabitation in Italy (Rosina and Fraboni 2004). Using an individual level diffusion model, we obtain results that are consistent with the crucial role that family ties play in the choice of cohabitation instead of (or be-fore) marriage. The paper is organized as follows: The next section presents the theoretical back ground and argues that the study of cohabitation in Italy needs to consider the role of family ties. To test our hypothesis, we use an approach proposed by Nazio and Blossfeld (2003), and slightly modify it in order to catch adequately the specificity of the Italian context, as will be highlighted in Section 3. …