Partnership research projects between academic researchers, service providers, policy makers, and persons from vulnerable populations are increasingly promoted as a means to inform and improve research and practice. Key elements in partnership research are the participation of multiple stakeholders and a shared responsibility and control over ideas, processes, and outcomes. This sounds clear, yet it is susceptible to various interpretations and coloring, creating the risk of unbalanced power between stakeholders and researcher. In this article, we present a case study in which partnership research is applied in the form of multistakeholder participation. In combination with theoretical concepts, we provide insight into how a partnership based on a nonhierarchical relationship between stakeholders and researcher is developed. We highlight three issues, being the reach, the depth of participation, and the power dynamics between stakeholders and researcher. The findings presented here focus on the partnership research process and the participation of multiple stakeholders as partners. Further research is needed to gain insight in the effectiveness of partnership research, that is, in how a partnership succeeds or fails to reach research goals, for example, improvement of practice, impact, and empowerment of stakeholders.