There are significant country-specific differences in the degree of women’s labor market integration and working time patterns after the birth of a child. Birgit Pfau-Effinger discusses how it is possible to explain cross-national differences in women’s work-childcare behavior. She argues that common approaches to the role of family policy for women’s employment tend to neglect the role of cultural ideas and often do not sufficiently theorize the relationship between culture and family policy. The chapter introduces a complex multilevel approach to theorizing how the interrelation between culture and family policy in their role for women’s (and men’s) work-childcare behaviors operate. This approach also theorizes which causal mechanisms and processes in the multilevel system it is based on. Main elements include a multilevel concept of culture, the concept of the relative autonomy of culture and family policy institutions, the theorization of women’s work-childcare behavior in the context of culture and family policy institutions and the role of informal and market-based resources for childcare.