This article focuses on collaborative governance and the challenge of participatory processes in order to form integrated adaptation responses to climate change. The case of Santiago de Chile, where the creation of a regional Climate Change Adaptation Plan for the Metropolitan Region was undertaken in collaboration with the Regional Government and the Regional Ministerial Secretariat of the Environment, provides the experience of such a participatory process being part of a larger inter- and transdisciplinary project. The article highlights the complexities involved in this process and knowledge transfer in the context of collaborative governance. The principal challenges identified are: to ‘make the case’ with respect to climate change adaptation planning; to be able to communicate scientific data effectively and to be clear about methodologies and uncertainties; and to ensure an integrated, coordinated response rather than sectoral fragmentation. The paper concludes that despite the complexities involved, participatory planning processes are preferable for urban climate change adaptation, as such processes are more legitimate and generate the social capacity building and inter-sectoral cooperation needed in the context of the current governance models in large Latin American cities, as exemplified by the case of Santiago.