Researchers responding to femicide and violence against women and girls (VAWG) face significant challenges around accessing complete and coordinated data. To delve further into understanding femicide data sources, the chapter brought together key stakeholders working to improve data collection on femicide in various world regions to engage in a collaborative reflection process. During the collaborative process, the following seven themes emerged: (1) research goals, (2) accessibility of accurate data, (3) lack of coordination and standardisation across data collection, (4) data completeness, (5) the role of qualitative data in femicide prevention, (6) emotional toll, and (7) achievements. The stakeholders shared that in most world regions, femicide data are dependent on administrative data sources on homicide, which may be flawed or entirely non-existent. When data is accessible by researchers, variables pertaining to information such as individual-level characteristics, gender-related motives, and other contextual information is incomplete. Femicide data is further complicated by uncoordinated legal definitions and parameters. Without comprehensive and reliable data sources on the killings of women, many stakeholders are limited in the information they can use to support their specific prevention efforts. Although challenges remain with femicide data collection and analysis, all stakeholders voiced optimism about recent achievements in the field. It is crucial to reflect on homicide data gaps and conceptualizations of femicide data to strengthen research and prevention efforts.