Employing a new measure of legislative leadership equity, this article compares political conditions under which quotas are adopted across 18 African countries and the extent to which women reach leadership positions following the implementation of a quota. Levels of political competition and women's mainstream political activity at the time of gender quota adoption indicate how the interests of political parties shape the design and effects of the law. The outcomes of gender quotas are highly contingent on adoption context which suggests the need for academics and policy makers to analyze the politics behind these measures to develop country-specific approaches for empowering women in politics.