Trust is widely recognised is a core feature of partnership relationships and one that facilitates joint work. It is an issue that must be addressed if partnerships are to enhance service system integration. In recent literature trust has been linked to concepts of risk and control. In this study of trust within a Primary Care Partnership (PCP) in Australia the experiences of risk and uncertainty, and control, of participants in different structural positions, were explored in detail. The data used in this paper was qualitative, derived from 63 interviews with managers and service providers participating in committees of the PCP. This paper reports on the differences in the experience of risk and uncertainty, trust and control, of managers and service providers working as boundary spanners through the committees of a PCP. For managers there were significant risks and uncertainties, and trust and control were important. For service providers there were few risks and uncertainties, and trust and control were of much less importance. Some policy implications of the differences in perspective are discussed, as are important areas for further research.