During his diplomatic career, Pfirter held various positions at the
Argentine Foreign Ministry. In 1992 he was promoted to the rank of Ambassador and in the same year he became the Director of the Argentine-Brazilian Agency for Accounting and Control of Nuclear Materials (ABACC) and the Director of the Argentine Space Agency (CONAE). He was subsequently appointed Undersecretary for Foreign Policy at the Argentine Foreign Ministry. From 1995 to 2000, during the presidency of
Carlos Menem, Pfirter was Argentina's ambassador to the
United Kingdom. In 2002, Pfirter was unanimously elected the Director-General of the Organisation for the Prohibition of Chemical Weapons (OPCW) in The Hague, The Netherlands. He was elected for a second term in 2006. Pfirter's tenure was praised as a time of consolidation and strengthening of the OPCW after the controversial departure of his predecessor
José Bustani. Pfirter gathered support for chemical weapons destruction and as a manager he succeeded in administering the Secretariat with zero nominal growth (ZNG) for four years in a row. After retiring in 2010, he became a member of the Global Council on Weapons of Mass Destruction at the
World Economic Forum. From 2015 to 2019, Pfirter was Argentina's ambassador to the
Holy See. Pfirter was appointed by President
Mauricio Macri to succeed
Eduardo Valdés, upon
Pope Francis's suggestion. ==Awards==