Ecosystem services have rapidly moved to the mainstream of environmental policies. Certification has for decades been a market-based tool for sustainability. Here, we assess whether certification of ecosystem services supports forest management and conservation. We look at forest ecosystem services, such as water regulation, carbon sequestration, and pollination provision, and evaluate the opportunities and constraints for developing systems to certify them. We discuss a series of challenges, and suggest that caution is needed: insufficient demand for multiple services, high biophysical service complexity, and elevated monitoring costs all indicate that opportunities for large-scale commercial viability of certified forest ecosystem services are limited. While some certification already exists for forest carbon services, we expect the certification of other services to remain a minor niche that seldom justifies major subsidies.