Despite widespread enthusiasm for broader participation in health policy and programming, little is known about the ways in which multi-sector groups address the challenges that arise in pursuing this goal. Based on the experience of Peru's National Multi-sector Health Coordinating Body (CONAMUSA), this article characterizes these challenges and identifies organizational strategies the group has adopted to overcome them. Comprising nine government ministries, nongovernmental organizations, academia, religious institutions, and international cooperation agencies, CONAMUSA has faced three principal challenges: 1) selecting representatives, 2) balancing membership and leadership across sectors, and 3) negotiating role transition and conflict. In response, the group has instituted a rotation system for formal leadership responsibiliti es, and professionalized management functions; created electoral systems for civil society; and developed conflict of interest guidelines. This case study offers lessons for other countries trying to configure multi-sector groups, and for donors who mandate their creation, tempering unbridled idealism toward inclusive participation with a dose of healthy realism and practical adaptation.