This study analyzes whether and how family policies are related to women’s first and second child transitions in 21 post-industrial countries. We adapt the social investment approach developed in welfare state research and distinguish between investment-oriented family policies and traditional, protection-oriented family policies. Our family policy indicators vary over time and are merged with fertility histories provided by harmonized individual level data. We use multilevel event-history models and control for time-varying unobserved heterogeneity at the country level and individual-level characteristics. Higher family-policy support of both types is correlated with the postponement of first births, particularly among young women, whereas traditional-family support is also correlated with postponement among older women and women in education. Both types of family support are linked to earlier first births among lower educated women. Only investment-oriented support is correlated with second birth transitions and this positive relationship does not vary for women with different educational levels.