The study investigates traditional knowledge of forest plants in a community (La Quetzal) inhabited by people who returned to Guatemala at the end of the civil war, after 10-12 years in exile in Southern Mexico, and now are in the process of constructing a new community in the Lacandon jungle in the Petén, Guatemala. We ask if the basis of knowledge and the use of natural resources change when people migrate. The relevance of vascular plant diversity for consumption and other daily needs of the population is explored. Relatively few species are presently used, with the exception of timber species, where knowledge seems to be increasing. Traditional knowledge has been maintained in certain areas such as medicine. Nature as such is regarded as important primarily as potential monetary capital and not for its subsistence capital. We find that the refugee situation has led to the introduction of global consumption patterns. Still there continues to be a dynamic local intuitive knowledge arising directly from practical experiences. Two interlinked factors have been the driving forces altering the knowledge and the use of natural resources by the people in La Quetzal: Change in the natural environment and change in the social and economic environment.