Payments for environmental services (PES) are increasingly discussed as appropriate mechanisms for matching the demand for environmental services with the incentives of land users whose actions modify the supply of those environmental services. While there has been considerable discussion of the institutional mechanisms for PES, relatively little attention has been given to the inter-relationships between PES institutions and other rural institutions. This paper presents and builds upon the proposition that both the function and welfare effects of PES institutions depend crucially on the co-institutions of collective action (CA) and property rights (PR).