Ethnic minority and low-income populations have some of the highest rates of cardiovascular disease (CVD) and the highest rates of physical inactivity, an independent risk factor for CVD. Ethnic minority and low-income women are especially at risk. Because programs designed to increase physical activity have the potential to reduce CVD rates in specific populations, research in this area is expanding. As part of the Women's Cardiovascular Health Network funded by the Centers for Disease Control and Prevention, the goal of this multi-site project is to identify factors, particularly environmental, policy, and cultural factors, that may influence physical activity among ethnic minority and low-income women ages 20-50 years. To achieve this goal, 42 focus groups were conducted in various locations throughout the United States with African American, American Indian, Latina and White women. Groups represented both urban and rural living environments. This article explains the basis for this project and the methodology used. Other articles in this series explain the results from the focus groups in detail.