There is consensus that community-wide integration of programs targeting pediatric obesity prevention is needed. The present article describes the growth, acceptability, and impact of a school- and community-based kids' marathon program targeting physical activity and nutrition. Youth in the program are encouraged to incrementally walk/run/jog a marathon and improve their diet through nutrition challenges. Participants track mileage and healthy eating over approximately 6 months, and complete a final marathon mile at the program's culminating event. Across 21 schools, 404 students between kindergarten and 8th grade reported on their experiences in the program. Also, 19 school coordinators rated their perceptions of the program's impact. While the data is preliminary and retrospective, it indicates that participants are highly engaged and that the program has potential to improve physical activity and other healthy lifestyle behaviors in many children. Strengths of the program, implications for obesity prevention, and future directions are also discussed.