In 2002, the U.S. Environmental Protection Agency (EPA) released its Asthma Research Strategy. Since then, scientists have made significant strides in advancing our understanding of how and why asthma is on the rise and our understanding of what induces and exacerbates the disease. EPA research has focused on three areas: asthma triggers, susceptibility factors, and intervention strategies. This document provides an overview of the advances in these areas and highlights studies that are particularly noteworthy because of their contribution to applications that reduce asthma suffered by individuals. This research reflects EPAs commitment to addressing the serious public health threat that is posed by the growing asthma epidemic. While we are proud of the accomplishments of EPAs Asthma Research Program to date, significant uncertainties remain. We need to learn more about the causes and triggers of asthma, as well as how to manage this disease.