Although there has been an increase in representation of women in national and state legislatures, women still hold much fewer than half the seats in most chambers. Research on women in legislatures has addressed questions such as why there are still few women legislators despite constituting at least half the population, whether women view the job of representative differently than men, or whether they behave differently in the chamber, or have different legislative agendas. This chapterexamines the issue of gender in the legislatures, focusing on how to get women into the legislature and what women do once they are there. It begins with a brief review of the evolution of the research field and summarizes findings about institutional factors that help women get elected. It then considers whether women differ from men in the legislature in terms of behavior. Finally, it highlights challenges for moving the field of gender and parliaments forward and argues for greater attention to intersectionality, operationalizing of women’s interests, and the political opportunity structure faced by politically ambitious politicians.