This article highlights the progress in building a knowledge base on effective ways to increase access to justice for women who have experienced gender-based violence, offer quality services to survivors, and reduce levels of gender-based violence. While recognizing the limited number of high-quality studies on program effectiveness, this review of the literature highlights emerging good practices. Much progress has recently been made in measuring gender-based violence, most notably through a World Health Organization multicountry study and Demographic and Health Surveys. Even so, country coverage is still limited, and much of the information from other data sources cannot be meaningfully compared because of differences in how intimate partner violence is measured and reported. The dearth of high-quality evaluations means that policy recommendations in the short run must be based on emerging evidence in developing economies (process evaluations, qualitative evaluations, and imperfectly designed impact evaluations) and on more rigorous impact evaluations from developed countries.