ParticipACTION is a Canadian physical activity communications and social marketing organization that has been relaunched in 2007 after a 6-year hiatus. The purpose of this study is to qualitatively identify and describe the expectations and challenges the relaunch of the new ParticipACTION may present for existing physical activity organizations. Using a purposeful sampling strategy, the authors conduct semistructured telephone interviews with 49 key informants representing a range of national, provincial, and local organizations with a mandate to promote physical activity. Overall, there is strong support in seeing ParticipACTION relaunched. However, organizational expectations and/or their ideal vision for it are mixed. Organizations envision and support its performing an overarching social marketing and advocacy role, and in providing tools and resources that supplement existing organizational activities. Four major organizational challenges are identified concerning overlapping mandates, partnership and leadership concerns, competition for funding, and capacity concerns. Social marketing initiatives, such as ParticipACTION, may not be able to maximize their impact unless they address the expectations and concerns of competing organizations with a mandate to promote physical activity.