Researchers have identified as effective and worthy of broader dissemination a variety of intervention strategies to promote physical activity among older adults. This paper reports results of a community-organizing approach to disseminating evidence-based interventions in a sustainable way: The Southeast Seattle Senior Physical Activity Network (SESPAN). SESPAN was implemented in Southeast Seattle, a group of multicultural neighborhoods extending 8 miles southeast of downtown Seattle, with a population of 56,469 in 2000, with 12% (7,041) aged 65 and older. The SESPAN organizing strategy involved networking to: (1) make connections between two or more community organizations to create new senior physical activity programs; and (2) build coalitions of community groups and organizations to assist in making larger scale environmental and policy changes to increase senior physical activity. The SESPAN evaluation used an uncontrolled prospective design focusing on sustainable community changes, including new or modified programs, policies, and practices. Networking among organizations led to the creation of 16 ongoing exercise classes and walking groups, serving approximately 200 older adults in previously underserved Southeast Seattle communities. In addition, the project's health coalition is sustaining current activities and generating new programs and environmental changes. The success of the SESPAN organizing model depended on identifying and involving champions in partner organizations who provided support and resources for implementing programs.