To implement sustainable health-promoting structures in a setting, various agents must work together. In the Capital4Health research network, participatory stakeholder groups consisting of key persons, stakeholders, representatives of the target group, and facilitating experts are assembled in five settings (child care center, school, company, rural community, nursing home). In a Cooperative Planning process, the various groups meet regularly to plan and implement strategies to promote physical activity across different settings. This study evaluates whether participatory stakeholder groups have been established and also examines the capacity-building processes that took place in these stakeholder groups. For process evaluation, 78 group meetings were documented in 16 different stakeholder groups using a semi-structured protocol based on established capacity-building domains. For outcome evaluation, six semi-structured interviews (1-2 per setting) with facilitating experts were conducted. Data were analyzed by content analysis. Across all settings, capacity-building processes were successful to a certain degree (e.g. problem assessment, resource mobilization). However, in most groups it was difficult to broadly assess problems, to establish sustainable networks, or to find persons with leadership characteristics. Also, irregular participation, lack of motivation to take over responsibility, and minimal institutional readiness for structural and personal changes often hindered the progress of the projects. Stakeholder groups can actively involve setting members in the development of physical activity promotion programs. It seems challenging, however, to sustainably establish such groups that continue working independently without assistance from a facilitating expert.