A physical activity intervention applied principles of community-based participatory research, the community-based prevention marketing framework, and social cognitive theory. A nonrandomized design included women ages 35 to 54 in the southeastern United States. Women (n = 430 preprogram, n = 217 postprogram) enrolled in a 24-week behavioral intervention and were exposed to a media campaign. They were compared to cross-sectional survey samples at pre- (n = 245) and postprogram (n = 820) from the media exposed county and a no-intervention county (n = 234 pre, n = 822 post). Women in the behavioral intervention had statistically significant positive changes on physical activity minutes, walking, park and trail use, knowledge of mapped routes and exercise partner, and negative change on exercise self-efficacy. Media exposed women had statistically significant pre- to postprogram differences on knowledge of mapped routes. No-intervention women had significant pre- to postprogram differences on physical activity minutes, walking, and knowledge of mapped routes. (Contains 3 tables and 1 figure.)