This paper assesses the scale of the potential co-benefits for residents of developing countries of protecting forest ecosystems in order to mitigate climate change. The objective is to improve understanding among development practitioners of the ways in which services provided by forest ecosystems can also make important contributions to achieving development objectives such as improvements to health and safety, and maintenance of food and energy security. This is achieved by reviewing empirical studies that estimate the value of specific ecosystem services derived from forests in order to evaluate and describe the current state of knowledge on how the wellbeing of local people is likely to be affected by the introduction of global mechanisms for avoided deforestation in developing countries. There are four main ways in which wellbeing can be affected: 1) forests provide soil protection and water regulation services, which in turn reduce waterborne diseases, maintain irrigation water supply, and mitigate risks of natural disaster; 2) forests provide habitat for birds, fish, mammals and insects that affect human health and income generation opportunities; 3) clearing forest through use of fire can lead to respiratory illness and property damage, particularly if the fires spread accidentally; and 4) tropical forests are particularly high in biodiversity, making them important locally as well as globally as a potential source of genetic material for new crop varieties and pharmaceuticals. Evidence on the size of these benefits suggests that while they are highly variable, households in or near forests and poor households benefit most from forest ecosystem services.