Women's political participation and representation vary dramatically within and between countries. We selectively review the literature on gender in politics, focusing on women's formal political participation. We discuss both traditional explanations for women's political participation and representation, such as the supply of women and the demand for women, and newer explanations such as the role of international actors and gender quotas. We also ask whether women are distinctive; does having more women in office make a difference to public policy? Throughout (...) the review we demonstrate that a full understanding of women's political representation requires both deep knowledge of individual cases such as the United States and broad knowledge comparing women's participation across countries. We end with four recommended directions for future research: (a) globalizing theory and research, (b) expanding data collection, (c) remembering alternative forms of women's agency, and (d) addressing intersectionality. (shrink)