This paper proposes methodology and provides practical tips for associating plant and animal names of little-known languages with scientific designations, especially for the purpose of producing accurate dictionary entries. The focus is on how a linguist can accomplish this task with or without the assistance of biologists, while avoiding the unsound practice of relying solely on vernacular names in the contact language. The points presented here are illustrated with examples from Matses, a language in the Panoan family spoken by an indigenous society living in western Amazonia, with whom the author has conducted extensive zoological, ethnobiological and linguistic field research. © 2007, Akademie Verlag. All rights reserved.