While the Scandinavian countries are well-known for their gender-egalitarian policies, there are important intra-Scandinavian policy differences. Through a comparative-historical analysis of Norway and Sweden, this article illustrates how structural factors (economic and political) and ideational factors (gender and religion) interact and combine to produce the particular national policy outcomes in the post- Second World War period, using public childcare as a comparative case study. The economic developments pursued by the countries in the postwar period are key to understanding the political party dynamics, the perpetuation (or lack thereof) of religious and centre-periphery cleavages, as well as the change in the political leadership's gender-ideological orientations, and the consequences of these factors for the evolution of public childcare policy. Norway has no institutionalised childcare guarantee, private ownership of childcare is high and religion plays a role in the national preschool curriculum. In contrast, Sweden has a binding national childcare guarantee, public ownership remains high and religion plays no role in the preschool curriculum. The policy differences are theoretically interesting as factors commonly hypothesised as important to gender-egalitarian policy outcome – on their own, or combined – cannot explain these differences. Thus, this article contributes important knowledge about the causal mechanisms behind gender-egalitarian policy development. The study fills a gap in the comparative welfare state literature by showing how structural and ideational factors are mutually reinforcing.