Despite significant international initiatives, the gender wage gap seems to persist and in the more recent past has even shown effects of reinforcement. While traditional factors such as education, at least in developed countries, seem to play a negligible role, more modern influences such as the division of labor, mostly based on the birth of children, are having an impact on wage discrepancies between men and women. Using data from the Swiss Household Panel, this paper analyses if this so-called motherhood wage penalty for women exists in Switzerland and what its effects are. The findings from the event-driven regression method show, that depending on the years since the birth of the first child, women earn between 20 and 40% less than men, controlling for characteristics such as age, education and labor-related features. According to the analysis, most of the motherhood wage penalty is due to a significant reduction in women’s workload compared to men’s, which also results in lower career opportunities. Furthermore, findings from robustness checks show that even when controlling for full-time individuals, there seems to be a motherhood wage penalty, as women’s wages tend to grow at slower rate than men’s after the birth of the first child.