--- - |2 Abstract The process of union formation and the context of childrearing have profoundly changed with the spread of cohabitation in the last few decades. It is only recently that some attention has been paid to the implications of these changes for family ties. This study considers, with reference to Italy, a specific relationship between individuals in couples and their family of origin – childcare by grandparents. The aim of the paper is twofold. First, we investigate whether children of cohabiting couples are cared for by their grandparents to a lower extent compared to children of married couples. Second, the current study examines whether potential differences decrease over time. The data used are from two rounds of cross‐sectional and nationally representative survey conducted in Italy in 2003 and in 2009. Our results show that in 2003 both in the provision and the intensity of grandparents’ childcare, children of cohabiting parents were less likely to have their grandparents involved than children of married parents. However, the differences between marriages and cohabitations disappear in recent years. - 'The British Journal of Sociology, Volume 69, Issue 3, Page 580-600, September 2018. '