In this work we aim at presenting and interpreting the use and meaning of plants in traditional veterinary in Sierra de Ancasti (Catamarca, Argentina). By employing ethnobotanical research methods and techniques, we registered taxa of vernacular ailments and 62 medicinal uses corresponding to 43 species from 30 botanical families. They are used medicinally due to their healing, digestive, anti-parasitic and oxytocic properties. In addition, the role of toxic and dangerous species was analyzed in the local veterinary. Together with the repertoire of plants, we also described other popular therapeutic techniques and cultural practices of religious-ritualistic nature. Finally, tension was analyzed between tradition and modernity in this field of knowledge. It has been concluded that, despite ethnoveterinary knowledge is relevant for many species and uses, its practice is being gradually neglected, which could eventually lead to the extinction of experience. © 2017 Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas.