International debates on climate change have been arguing the need to foster adaptation planning in Latin America where impacts are expected to be more significant given the vulnerable socio-economic context and reliance on natural resources. However little progress has been made both at national and at community level due to the complexity of adaptation planning in these countries, and due to the difficulty in managing socio-environmental dynamics characterized by deep uncertainties, potential tensions in cross-scale interactions among scientists, policy makers and local communities among others. This four-year project helped local communities, Civil Society Organizations (CSO) and scientists in Latin America and Europe in engaging in inter-disciplinary action-research to increase their collective capacity to adapt to climate change. EcoAdapt focused on water security as a mobilizing issue that is i) critical due to climate and societal changes; ii) is linked to social tensions; iii) is key for the livelihood of local communities. EcoAdapt consortium was made of 5 CSO partners and 4 RTD partners who joined forces to address water security in “Model Forest” landscapes in Argentina (Jujuy), Bolivia (Quiquitano), and Chile (Alto Malleco). Knowledge sharing formed the backbone of the project and was done in such a way that partners develop a critical view of their own sources of knowledge, which fostered the creation of new, socially-validated knowledge. It has also provided scientists and policy-makers with an in-depth insight into local knowledge and issues, which framed the identification of knowledge gaps and the research to be done. We confirmed that adaptation to climate change goes way beyond coping and is not something that can be done in isolation by any player at any organization level. EcoAdapt developed studies, tools, training material, strategic adaptation plans for water security, and implemented several adaptation pilot projects for the benefit of margi