In this article, we provide insight into sharing power and balancing practitioner and researcher priorities during the process of establishing a research agenda for a research-practice partnership (RPP). We draw on the literature about effective collaboration within RPPs to identify concepts and factors that can help or hinder the research agenda-setting process. Concepts include boundary spanning, spheres of interest and action, and strategic knowledge leadership. Factors include early and ongoing engagement of partners, adequate representation of diverse perspectives, funder priorities, and the presence of trusting relationships. The authors then use examples from our own experiences in RPPs to illustrate how these concepts and factors play out in the agenda-setting process. (author abstract)