The randomized controlled trial is commonly used by both epidemiologists and economists to test the effectiveness of public health interventions. Yet we have noticed differences in practice between the two disciplines. In this article, we propose that there are some underlying differences between the disciplines in the way trials are used, how they are conducted and how results from trials are reported and disseminated. We hypothesize that evidence-based public health could be strengthened by understanding these differences, harvesting best-practice across the disciplines and breaking down communication barriers between economists and epidemiologists who conduct trials of public health interventions.