AbstractWe offer an example of modeling that influenced global health policy related to polio and we provide some insights about the modeling process. Although system dynamics lies at the heart of our modeling, we emphasize that downplaying the modeling to focus on the policy questions played a critical role in the use of the results by decision makers. Here we provide details of the system dynamics modeling that underlies our research on polio, and discuss the process we followed to bring scientific modeling of a highly complex issue to policymakers. We hope that providing a better understanding of our efforts and describing our continuing analytical journey provides useful insights for others who seek to use system dynamics to develop policies that matter. Copyright © 2009 John Wiley & Sons, Ltd.