The main purpose of this article is to provide an account of Darrell Posey’s academic life, from a north-American undergraduate student interested in entomology into one of the main figures and builders of Ethnobiology and major advocate of Indigenous Peoples ‘rights around the world. This short biography highlights his relations with the Kayapó indigenous people and his role in coordinating a decade-long interdisciplinary ethnobiology research project named “The Kayapó Project”. It was mostly through the development of this team effort that he contributed fundamental and long-lasting theoretical, methodological and practical advancements to the field of ethnobiology.