This chapter investigates women's efforts to "engender" policymaking and policy—to increase the numbers of women involved in the policy process and to generate more equitable policy initiatives. It examines emergence of gender equality initiatives to transnational interventions early in the twentieth century, which encouraged governments to create national "machineries" to improve the condition and status of women. The chapter explores the proliferation of women's policy agencies in nations around the world and their institutionalization in some nations as state feminism. It evaluates the range of those forms and the challenges that proponents of equality policies face working within states that are themselves structured by gendered institutions. The chapter analyzes the forces that constrain women's policy agencies in various regions of the world. It considers gender mainstreaming, policy intended to incorporate concerns gender equality in all units of every government agency. The chapter traces the diverse meanings of gender mainstreaming to illuminate the politics of equality in the twenty-first century.