The present study focused on the question of why couples change their division of paid and unpaid labor when they become parents. The knowledge of changes during the transition to parenthood is well-established in previous research and quite stable in various countries. Extending this knowledge, the aim was to examine how couples, on the point of becoming mothers and fathers, perceived and explained these changes in their division of employment and housework, in what way they anticipated them, and how they explained unexpected changes. This analysis was done for West German couples as the western part of Germany is an example for the combination of a conservative welfare state that supports the male breadwinner norm, and parenthood ideals that increasingly suggest fathers’ active involvement in childcare and mothers’ labor market activity. In order to gain insight into couples’ decision-making processes, a qualitative research design was used.