Abstract: Although more than half of the parliamentarians are parents (Campbell and Childs 2014; SRF 2019) we know very little about mothers in parliament and virtually nothing about fathers. How does having a child, particularly a young child, affect the political behavior and success of parliamentarians? We answer this question by analyzing the parliamentary offices and political behavior of all Swiss national parliamentarians since 2011 (until 2020). Raising children is costly in terms of money and requires time and attention. However, the responsibility and care for children are often shared unequally between the parents and the social expectations of mothers differ from those fathers have to meet. Hence, we expect and find the effect of parenthood to differ between men and women: while mothers are less likely to be successful, fathers are rewarded in parliament.