Outdoor air pollution and the indoor environment have been shown to cause or exacerbate childhood asthma. Allies Against Asthma coalitions implemented a broad range of activities to reduce or remediate indoor exposure to asthma environmental triggers for children with asthma including education and trigger remediation, physician and other health care provider education, and policy efforts to improve air quality in homes and schools. Outdoor environmental triggers were addressed through programs to increase education and awareness and efforts to change policies related to environmental conditions. Implementation of such efforts was complicated by the lack of safe and affordable housing and the amount of time and resources necessary to address policy change. Keys to success included promoting coordination and partnerships among coalition members, implementation of consistent messages, and building a broad and unified voice for policy change.