January 1, 2003 - December 31, 2006
| President: | John M. Ball | (United Kingdom) |
| Vice-Presidents: | Jean-Michel Bismut | (France) |
| Masaki Kashiwara | (Japan) | |
| Secretary: | Phillip A. Griffiths | (USA) |
| Members at Large: | Andrey A. Bolibruch | (Russia, deceased 2003) |
| Martin Grötschel | (Germany) | |
| Zhi-Ming Ma | (China) | |
| Ragni Piene | (Norway) | |
| Madabusi S. Raghunathan | (India) | |
| Victor Vassiliev | (Russia, since 2004) | |
| Ex-officio: | Jacob Palis (Past President) | (Brazil) |
January 1, 2003 - December 31, 2006
| Chair: | Paulo Domingos Cordaro | (Brazil) |
| Secretary: | C. Herbert Clemens | (USA) |
| Members at Large: | Hajer Bahouri | (Tunisia) |
| Graciela L. Boente Boente | (Argentina) | |
| Shrikrishna G. Dani | (India) | |
| Gérard Gonzalez-Sprinberg | (France) | |
| Fazal M. Mahomed | (South Africa) | |
| Toshikazu Sunada | (Japan) | |
| Jiping Zhang | (China) |
January 1, 2003 - December 31, 2006
| President: | Hyman Bass | (USA) |
| Vice Presidents: | Jill Adler | (South Africa) |
| Michèle Artigue | (France) | |
| Secretary-General: | Bernard R. Hodgson | (Canada) |
| Members at Large: | Carmen Batanero | (Spain) |
| Mary Elizabeth Falk de Losada | (Colombia) | |
| Nikolai Dolbilin | (Russia) | |
| Peter Lawrence Galbraith | (Australia) | |
| Petar Stoyanov Kenderov | (Bulgaria) | |
| Frederick K.S. Leung | (Hong Kong) |
January 1, 2003 - December 31, 2006
| Members at Large: | Jeremy John Gray | (United Kingdom) |
| Wenlin Li | (China) |
January 1, 2003 - December 31, 2006
| Committee Members: | Pierre Bérard, | Mathematics Université Joseph Fourier, Grenoble, France |
| Jonathan M. Borwein | Simon Fraser University, Burnaby, BC, Canada | |
| John Ewing | American Mathematical Society, Providence, USA | |
| Martin Grötschel | Konrad-Zuse-Zentrum, Berlin, Germany | |
| Rolf Jeltsch | ETH Zurich, Switzerland | |
| Alejandro Jofre | Universidad de Chile, Chile | |
| Peter W. Michor | Universität Wien, Austria | |
| David Morrison | Duke University, Durham, USA | |
| David Mumford | Brown University, Providence, USA | |
| Alf van der Poorten | Macquarie University, Sydney, Australia |