Are men and women legislators equally loyal to their parties? We theorize that parties select candidates based on gendered criteria, leading to the (s)election of more disciplined women. Moreover, we argue that gendered expectations about proper behavior limit women legislators’ ability to act independently from their parties. Using surveys from over 800 parliamentarians across 17 African legislatures, we find that women report significantly higher levels of party discipline than do their men copartisans. From this survey data and new legislative speech data, we also find support for our proposed causal mechanisms. Further, we find that among women parliamentarians, party discipline is negatively correlated with the prioritization of womens rights. A qualitative case study of the Namibian Parliament illustrates our findings. We discuss the implications of our results for women’s legislative effectiveness, for the substantive representation of women’s interests in policy making, and for the continued democratization of emerging party systems.