Corrado Pirzio-Biroli was member of the Cabinet of Commission President Gaston Thorn in charge of the EU budget, economic and financial affairs, transport, energy and EURATOM from 1982 to 1984. From 1985 to 1988 he was Deputy Head of Division "EFTA Affairs" in charge of the creation of a European Economic Area. From 1988 to 1992 he was Deputy Head of the EU Delegation in the United States, Washington DC, where he dealt in particular with political and commercial affairs. From 1992 to 1994 he was Head of the European Commission Delegation in Vienna, accredited to the Austrian
Government as well as to the United Nations, the UNIDO, and the Atomic Energy Agency, and a delegate to the Organization on Security and Cooperation in Europe (OSCE). From 1994 to the end of 2004, he was the Chief of Staff of Commissioner for Agriculture, Rural Development and Fisheries Franz Fischler. He was significantly involved in elaborating the Common Agriculture Policy (CAP) reforms of 1999 and 2003-2004 as member of the European Commission's five-person ad-hoc steering group. He also contributed to the elaboration of the first ever reform of the Common Fisheries Policy (2003), devoting substantial time to complement Franz Fischler's efforts in promoting two CAP reforms and the first EU Fisheries reform.