Payments for ecosystem or environmental services (PES) have become a popular biodiversity and forest conservation approach in the global South. Dozens of PES national programmes and hundreds of individual projects have been implemented across diverse geographies. This chapter reviews the evidence of a decade of PES implementation in the global South. This chapter examines how PES have delivered for the rural poor in these countries, looking specifically at any resulting impacts on local livelihoods and human wellbeing. Analyzing the benefits, costs and implications for the rural poor, this chapter shows that PES has to date delivered to the rural poor. Direct positive changes induced by PES include improvements in relative income and access to finance for public goods provision, the generation of a few jobs at a local level, gains in land management knowledge and skills, and the development of forest and biodiversity conservation activities, with relative low levels of labour input. Indirect effects include crowding-in, but at the same time increases in social conflict, negative environmental spill-overs, and rising inequality in access to income and resources. The social–ecological context where a PES programme is implemented is critical to the success of the programme.