This article undertakes an in-depth analysis of the evolution of Brazil’s Cooperation and Facilitation Investment Agreements (CFIAs) since the publication of the Brazilian Model CFIA in 2015. It studies the tumultuous history of investment treaties in Brazil and how it may have shaped Brazil’s response to the investor-State arbitration regime through the current model CFIA. It assesses how the reception of Brazil’s Model CFIA among Brazilian stakeholders and commentators may have influenced the trends and evolutions of the fourteen CFIAs signed by Brazil from 2015 to 2020. It argues that the Brazilian CFIAs have improved with time through the progressive narrowing and strengthening of their jurisdictional, substantial, public policy and dispute resolution clauses. At the same time, they may not have fully implemented the criticisms and comments of academia and Brazilian civil society, and some provisions remain to be clarified in the future.