The Clean Development Mechanism (CDM), a partnership tool founded under the Kyoto Protocol, grants potential opportunities to help developing countries achieve sustainable development. The present research examines the CDM projects in Eastern Europe (Moldova, Serbia, Bosnia and Herzegovina, Montenegro, and Albania). Although there were far fewer projects in this region than, for instance, China or India, it has some specific features that make it worth studying. Major findings are that most CDM projects in Eastern Europe involved a changing combination of two or more sources of financing, and the distribution of projects in the region was uneven. Moreover, although there was a small number of projects overall, they were all cost-effective, long-term and large-scale. The findings of the research call for improvements to be made to the governance of the CDM, by strengthening the international and national regulation of projects and by aggregating the scales of decision-making and actions so that real multi-scalar transnational governance — from the global level down to the local level — is implemented in a coherent manner. It is also recommended to carry out ex-post project evaluations, following which readjustments could be made.