The Bali Action Plan established that the design of a future international agreement must consider enhancing the developing countries participation in greenhouse gas mitigation activities in order to achieve the ultimate objective of the United Nations Framework Convention on Climate Change. Such participation should be appropriate to national circumstances and supported technologically and financially by the industrialized nations. This decision has generated particular interest because it implies a change in the way developing countries have until now faced their differentiated responsibility, with qualitative commitments to mitigation but not quantified obligations. In 2010, Chile communicated that it will achieve a 20% reduction below the 'business as usual' emissions growth trajectory in 2020. This paper first describes the progressive involvement of Chile in mitigation actions tasks with a periodization that shows the evolution of taking on obligations and opportunities within the framework of the Convention. In its final part, the paper elaborates on the last stage of this process and briefly presents progress as of mid-2012 on identifying Chile's (potential) Nationally Appropriate Mitigation Actions in the transport, agriculture and energy sectors. The assessment of the proposals of the more advanced cases analyzed concludes that the feasibility of realizing and achieving their objectives not only will depend on the availability of financial resources, but also, and primarily, on the political will of the Government.