The creation of ABACC and the Common System of Accounting and Control of Nuclear Materials (SCCC), a regional safeguards system with unique characteristics in the world, is the result of a process of confidence building and cooperation in the peaceful uses of the nuclear energy between Argentina and Brazil. In July 18, 1991, the Agreement between Argentina and Brazil for the Exclusively Pacific Use of Nuclear Energy (Bilateral Agreement) was signed. This Agreement that entered into force in December 1991, after its approval by the parliaments of the two countries, constitutes a founding milestone for ABACC. Thirty years after this milestone, it is worthy to review the process that led to its constitution, the main characteristics of the safeguards system that it applies and the insertion of this regional safeguards system in the framework of international safeguards, in which cooperation between ABACC and the International Atomic Energy Agency (IAEA) is of fundamental importance. This paper will describe the milestones in the establishment of ABACC and the SCCC, their main characteristics and the highlights of the implementation of regional safeguards over these three decades. It will also discuss the relevance of the cooperation in safeguards with focus on the current status of the cooperation between ABACC and the IAEA and the benefits of its future enhancement, concluding with some ideas about the challenges and opportunities that ABACC faces and the value of this unique model system established by Argentina and Brazil for the peaceful use of nuclear energy and non-proliferation.