Tree cavities are critical habitats for numerous vertebrate species, serving as keystone resources for nesting, roosting, and shelter. We document the first evidence of güiña breeding within a tree cavity of a standing dead tree, exploring its implications on breeding productivity and complementing this record with evidence from camera trap surveys conducted in temperate forests of central-south Chile. These findings enhance our understanding of the species’ natural history, breeding behavior, and habitat preferences. Additionally, we discuss the conservation implications of this discovery, offering new insights into the breeding ecology and habitat selection of one of South America’s most elusive felines.