A decade has passed since the Kyoto Protocol mechanisms were introduced to the international community as economic instrument aimed to mitigate climate change. The purpose of this work is to highlight the implementation of the Kyoto flexible mechanisms and their future role in the light of global climate change mitigation; also addresses the issues that should be considered while contracting for carbon credits under CDM/JI projects. In order to see how the flexible mechanisms have been implemented, the following issues are discussed: the project-based and market-based Kyoto mechanisms and their implementation during the first commitment period (2008-2012); legal nature of carbon credits as a form of emission rights; the development of carbon markets; legal instruments used for market transactions and risks allocation; as well as post-2012 challenges. Significant attention is devoted to the EU ETS, as of today the largest carbon market by volume and value of transactions, which involves 30 industrialised countries from Annex B of the Kyoto Protocol. The work will be useful for professionals working in energy sector, anyone interested in how the Kyoto Protocol mechanisms work.