Media advocacy is the strategic use of mass media and community organizing as a resource for advancing a social or public policy initiative. Across the United States, communities are using media advocacy to promote healthier public policies and environments. The U.S. Center for Substance Abuse Prevention commissioned numerous case studies of media advocacy on alcohol and tobacco issues in a diverse array of communities, including efforts in African-American and Latino communities or using computer-based electronic communication systems. The paper describes these efforts briefly, and summarizes lessons learned, including: media advocacy can lead to larger victories when used as a complement to community organizing in the context of a larger strategic vision for policy change; like policy advocacy, media advocacy is best done in the context of clear long-term goals; conscious framing, guiding the choice of spokespeople, visuals, and messages, can alter media coverage and public debate of health policies; advocates need to respect the media but also remember that they have power in relation to the media; and media advocacy is often controversial and not suited to every situation. The case studies show that media advocacy is a potent tool for public health workers, making an important contribution to campaigns to promote healthier public policies.