This rather unorthodox essay is a dialogue between an anthropologist and an epidemiologist, both of whom were involved with a large-scale collaborative ethnographic project exploring medical field studies, or ‘trial communities’, in western Kenya. Reflecting on their involvement with this project, the authors consider the pragmatics of what ‘collaboration’ represents in different disciplines and how it is enacted. The dialogue, which included a follow-up interview after the research was completed, highlights the expectations and tensions in such collaborative projects and offers the epidemiologist an opportunity to highlight the ideas, methods, and possibilities that he perceived as being ‘lost in translation’ between sociocultural anthropology and experimental medicine. We raise critical issues regarding the disjuncture between epidemiological and anthropological practices in research design, methods, epistemology, and collaboration, with the hopes of provoking more discussions regarding best practices in collaborative research projects.