The increasing influx of people moving to woodland environments in order to access social and natural amenities is generating conflicts which are becoming ever more intense and complex. Urban-forest interface issues are currently among the most serious and problematic issues for forest managers. The wildland-urban interface has grown in size in Patagonia because of an increase in area of human settlements intermingled with natural vegetation, giving rise to a disturbing new landscape dynamic associated with wildfires. Through laboratory tests we produced the first flammability plant list for northwest Patagonia, which includes exotic species that can frequently be found in wildland-urban interface areas. We identified groups of species according to live fine fuel characteristics and detected different types of flammability, based on ignitability and heat release. Our plant list allows comparison of native and exotic species, and the formulation of precautionary action to minimize environmental and economic risks.