Widespread social changes over the last half century have been reflected in changes in family forms. These changes have resulted in increased family diversity which, in turn, is reflected in the more diverse living arrangements experienced by children as they grow up. This paper is the first to provide reliable national estimates of the extent to which the living arrangements of Australian children have changed. Using relationship and fertility histories from the nationally representative Household, Income and Labour Dynamics in Australia household panel survey (HILDA), the analysis describes the changing patterns of living arrangements of 12,441 children between 1946-2001. Its methodology allows the examination of the different living arrangements experienced by children during the first 15 years of life and avoids the static analysis that relies on point-in-time estimates. Furthermore, unlike analysis that relies on official birth and divorce statistics, the present analysis is able to identify family changes experienced by children as a result of parental separation. Thus, it takes into account transitions related to parental cohabitation as well as marriage.