The demand to open up centers of power to public scrutiny has been expanding rapidly and on a global scale since the second half of the 20th century. In Brazil, the term transparency has been invoked with remarkable frequency in recent years as a solution to many of the nation’s problems. In 2011, the Access to Information Law was passed, which regulates the opening up of public bodies to citizens, and in the same year the country became a leader in the international Open Government Partnership (OGP) initiative. However, this was a belated step forward. While normative compliance with the principle of publicity only came about with the 1988 Constitution, many decrees, executive orders and laws have dealt with the protection of official secrets since Independence. With this in mind, this paper is dedicated to exploring aspects of the country’s history that allow us to trace the genesis and evolution of the dynamic between secrecy and transparency in Brazil, with the aim of analysing the limits and possibilities for the opening up and democratization of our foreign policy.