Dreams and dreaming practices are integrated into knowledge-building processes in many Indigenous societies. Therefore, these practices may represent a source of geographical and cartographic information. This article addresses their incorporation into collaborative and cross-cultural research methods, especially in the framework of participatory mapping projects conducted with Indigenous communities or organizations. It is argued that dreams and dreaming practices enable the consideration of Indigenous territorial dimensions, such as the sacred and the spiritual, as well as the presence of non-human actors, that are more difficult to grasp through the social sciences or modern Western mapping methodologies. In addition, this approach invites geographers and cartographers to adopt a culturally de-centered concept of the notions of territory, mapping and participation that goes beyond the positivist premises of Western science and its research methodologies. This text draws from a Mapuche counter-mapping and participatory mapping experience that took place in southern Chile between 2004 and 2006 and in which the author took part as a cartographer.