Substantial racial and ethnic disparities in health and health care exist in the United States. The Department of Health Policy at the Mount Sinai School of Medicine has developed a strategy for reducing those disparities that builds upon its quality improvement experience. This article discusses the utility of applying quality improvement principles to the development of interventions to eliminate underuse of effective treatments and reduce the disparities that may arise from this quality problem. We present a conceptual model of racial disparities in health and our underuse hypothesis. Parallels between our disparities research strategy and six sigma quality improvement methods are described. Finally, the article provides an example of how we have been able to successfully implement proven-effective health improvement programs in the Harlem community even after grant funding has ended.