Current definitions, instruments, and processes for measuring intimate partner violence, including sexual assault, are insufficient to detect the nature and scope of violence against all women. To remedy this problem, we recommend the use of community-based participatory research (CBPR) principles to develop culturally informed quantitative instruments that measure ethnic minority women’s experiences of intimate partner violence (IPV). CBPR requires community members and researchers to work equitably together throughout the research process, sharing decision-making and ownership. This paper identifies problems with current measurement approaches and describes the strengths and challenges of the CBPR approach. We argue that this research orientation offers the potential for “flexible standardization” that can provide better estimates of the extent of IPV and sexual assault, and provide communities with the knowledge they need to address these problems in a culturally sensitive manner