In March 2010, the Environmental Protection Agency (EPA) collaborated with government and nongovernmental organizations to host a groundbreaking symposium, "Strengthening Environmental Justice Research and Decision Making: A Symposium on the Science of Disproportionate Environmental Health Impacts." The symposium provided a forum for discourse on the state of scientific knowledge about factors identified by EPA that may contribute to higher burdens of environmental exposure or risk in racial/ethnic minorities and low-income populations. Also featured were discussions on how environmental justice considerations may be integrated into EPA's analytical and decision-making frameworks and on research needs for advancing the integration of environmental justice into environmental policymaking. We summarize key discussions and conclusions from the symposium and briefly introduce the articles in this issue.