This chapter presents the results of a participatory action-research strategy that led to the creation of a feminicide data standard. In response to the lack of homogenization in data collection of feminicide across the region, ILDA has worked in different contexts and with different partners throughout two iterations of the feminicide data standard project. In this chapter, we analyse the evolution of these two iterations through a participatory policy-making and capacity building lens. To conclude, we examine some of the best practices identified and set out some steps for the future.