Marcos Azambuja served as an Emeritus Trustee of the Brazilian Center for International Relations (CEBRI).

Served as Brazil's Ambassador to Argentina (1992–1997) and to France (1997–2003), and as Head of the Brazilian Delegation to the Disarmament and Human Rights Commission in Geneva (1989–1990).

He was Coordinator of the United Nations Conference on Environment and Development (the Rio Earth Summit – Rio 1992). At the Ministry of Foreign Affairs in Brazil, he served as Secretary-General (Vice Minister) and held diplomatic postings in London, Mexico City, and New York (United Nations). He was a member of the Weapons of Mass Destruction Commission and of the Tokyo Forum for Nuclear Non-Proliferation and Disarmament, and was also affiliated with institutions such as the Brazilian Historical and Geographical Institute (IHGB), the National Institute of Historic and Artistic Heritage (IPHAN), and the Roberto Marinho Foundation.