This article describes the extent to which Australian children experience family disruption caused by a change in their parents' marital / relationship status, and estimates the extent to which children live their childhood in particular living arrangements - in intact families, lone-parent families, and step or blended families. The approach adopted takes account of the dynamic nature of family living arrangements, rather than measuring living arrangements using single point in time, static measures. The analysis is based on data collected in the first wave of the Household, Income and Labour Dynamics (HILDA) survey conducted in 2001. Overall, this research indicates that the large majority of children spend most of their childhood in an intact family. Relatively few experience multiple transitions. For those who do face family disruptions, and multiple disruptions in particular, the challenge is to identify ways of assisting them and their parents in managing these transitions as well as possible and in ways that minimise the risk of negative outcomes.