Community-based participatory research (CBPR) refers to a methodological and epistemological approach to applied community projects in which researchers and community members collaborate as equals in the research process. Also known as participatory action research (PAR), CBPR has gained considerable acceptance both as a set of methods for identifying and addressing local issues of concern and as a vehicle for applying the principles of equity, cultural humility, mutual learning, and social justice to the relationships between researchers and communities. Although somewhat distinct from applied anthropology, CBPR shares with ethnography in particular an attentiveness to rapport building and community engagement and an overall validation of local knowledge. There is little consensus regarding the threshold of community participation necessary for a given research project to be considered CBPR. However, at a minimum the approach requires that community members define the problems to be assessed, provide consultation on the cultural and social dimensions of the study population, and serve in an advisory capacity over the entire project. The history of CBPR and its antecedents reflects its twin values as a pragmatic approach to researching and addressing local problems and as an emancipatory social justice project that seeks to diminish the hierarchical relationship between researchers and community members. Specifically, the pragmatic perspective was developed in the United States by social psychologist Kurt Lewin in the 1930s (and subsequently by the anthropologists Laura Thompson and Sol Tax), while the emancipatory approach derives from the work of educational theorist Paulo Freire in Brazil in the 1970s. Community Advisory Boards (CABs) play an outsized role in the success of CBPR projects, since they typically represent the community in these studies, and thus maintain oversight over all aspects of the research process, including the study design, sampling and recruitment protocols, and the dissemination of findings. Accordingly, nurturing and maintaining trust between researchers, the CAB, and the community constitutes a foundational practice for any CBPR study.