The many ecosystem services provided by forests (watershed protection, biodiversity conservation and carbon sequestration, for example) are gaining increasing attention from governments and the forest industry, as well as from private citizens. People are becoming aware of the dangers and costs of allowing forest services to be degraded or lost. The purpose of this article is to help policymakers assess the concerns and questions surrounding ecosystem services by providing a preliminary assessment of the status of markets for ecosystem services and their potential to contribute to tropical forest conservation.