This article explores the use of an action research (AR) approach with a marginalized population of people who trade sex and as a modality to engage diverse stakeholders to work together to reduce harm caused by sex trading. As a trained academic anthropologist thrust into leadership of a community research project, I cobbled together my own self-reflexive praxis and working method with the experts all around me – people who trade sex, police, residents, and more. In the process I discovered that involvement of women who traded sex in the project’s research design created a respectful, humane, connected, and acceptable research process in which participants felt comfortable sharing personal information. AR was better for participants and more useful in surfacing better and deeper knowledge of sex trading. It was also a cost-effective way to design a successful recruitment strategy to broaden the participant base of the study contacting participants not typically involved in research on sex trading. This is important because sampling is a perennial problem in studies of sex trading, prostitution, and sex trafficking. Our research led to new knowledge that formed the basis for action to reduce the harms of sex trading.