This research studies whether the Clean Development Mechanism (CDM) of the Kyoto Protocol achieves its objective of emission reductions in the host countries. It empirically investigates the impacts of CDM projects on CO2 emission reductions for 60 CDM host countries over 2005-10. This research makes use of the newly-developed econometric methods for dynamic panel data models associated with X-differencing procedure. It provides evidence in support of a decline in CO2 emissions in the CDM host countries. It has important policy implications that encourage the international community to support developing countries’ efforts towards low-carbon development via CDM projects.