This article seeks to analyse, comprehend and apprehend the appropriation processes of Ovide Decroly's ideas in Brazil through the translation of his books and that of Amélie Hamaïde into Portuguese. The article discusses the following questions. Why did Brazilian intellectuals and teachers need to import Decroly's ideas to be applied in Brazilian schools? Did the translation of Decroly's and Hamaïde's books play an innovative role in Brazilian society? Did the release of these books bring about changes, and did it stabilise and legitimise discourses that were already present in Brazil? Who were the translation agents of those books? First, discussions concerning travelling knowledge and cultural translation, as well as translation and the role of translation agents, are introduced. The translated books and their (production) contexts are then presented, comparing and analysing the source books and the translations. The analyses aim at understanding this journey and answering these questions, and it will be shown that Decroly's ideas were torn apart into "pieces of knowledge" gaining life and autonomy throughout the journey, and turning into facts. It is advocated that his ideas were appropriated as "indigenous foreigners" in Brazil.