The book explores the role of the Clean Development Mechanism (CDM), an offset mechanism under the Kyoto Protocol (art. 12), that allows the crediting of emission reductions from Greenhouse Gas (GHG) abatement projects in developing countries, and its contribution to Sustainable Development (SD) in Mexico. Through a sustainability assessment, the book analizes if and how CDM projects in Mexico are fulfilling one of the main objectives for which it was created and to what extent during the period 2005-2010. The main argument – besides the criticism about the efficiency and efficacy of the CDM itself- is that considering the extreme flexibility of SD criteria established by the Mexican government through the Designated National Authority (DNA), CDM projects have a relative impact on SD in some key dimensions such as environmental, economical, and to a lesser extent, social one. CDM relation with SD and its contribution in Mexico is however a complex topic to understand, partly due to the vague definition of SD adopted at country level and stakeholders positions towards the CDM itself.