The field of violence against women and girls has advanced considerably over the past two decades. We have much more information on the prevalence of violence in low and middle income countries as well as an expanding body of knowledge on risk and protective factors. This positions us well to develop and implement strong primary prevention interventions with a rigorous theory of change. However, there are still key gaps in our knowledge that need to be addressed in order to move towards more comprehensive models of intervention, and ultimately end VAWG. This provides a summary of existing evidence of what works and outlines the overarching research and innovation agenda for the What Works Global Programme.