(As of Sept. 5, 2006)
| Weight class | WBC | WBA |
|---|
| Heavyweight | Oleg Maskaev (Kazakhstan) | Nicolay Valuev (Russia) |
| Cruiserweight | O'Neil Bell (U.S.) | O'Neil Bell (U.S.) |
| Light heavyweight | Tomasz Adamek (Poland) | Fabrice Tiozzo (France) |
| Super middleweight | Markus Beyer (Germany) | Mikkel Kessler (Denmark) |
| Middleweight | Jermain Taylor (U.S.) | Jermain Taylor (U.S.) |
| Junior middleweight | Oscar De La Hoya (U.S.) | Jose Antonio Rivera (U.S.) |
| Welterweight | Carlos Baldomir (Argentina) | Ricky Hatton (England) |
| Junior welterweight | Vacant | Vacant |
| Lightweight | Diego Corrales (U.S.) | Juan Diaz (U.S.) |
| Super featherweight | Marco Antonio Barrera (Mexico) | Edwin Valero (Venezuela) |
| Featherweight | Takashi Koshimoto (Japan) | Chris John (Indonesia) |
| Super bantamweight | Israel Vazquez (Mexico) | Somsak Sithchatchawal (Thailand) |
| Bantamweight | Hozumi Hasegawa (Japan) | Wladimir Sidorenko (Ukraine) |
| Super flyweight | Masamori Tokuyama (Japan) | Nobuo Nashio (Japan) |
| Flyweight | Pongsaklek Wonjongkam (Thailand) | Lorenzo Parra (Venezuela) |
| Light flyweight | Omar Nino Romero (Mexico) | Koki Kamada (Japan) |
| Strawweight | Eagle Akakura (Thailand) | Yutaka Niida (Japan) |
| | | |
| Weight class | IBF | WBO |
|---|
| Heavyweight | Wladimir Klitschko (Ukraine) | Sergei Liakhovich (Belarus) |
| Cruiserweight | Vacant | Johnny Nelson (England) |
| Light heavyweight | Clinton Woods (England) | Zsolt Erdei (Hungary) |
| Super middleweight | Joe Calzaghe (Wales) | Joe Calzaghe (Wales) |
| Middleweight | Arthur Abraham (Germany) | Jermain Taylor (U.S.) |
| Junior middleweight | Roman Karmazin (Russia) | Sergei Dzindziruk (Ukraine) |
| Welterweight | Floyd Mayweather (U.S.) | Antonio Margarito (Mexico) |
| Junior welterweight | Juan Urango (Colombia) | Miguel Cotto (Puerto Rico) |
| Lightweight | Jesus Chavez (Mexico) | Acelino Frietas (Brazil) |
| Super featherweight | Gairy St. Clair (Australia) | Jorge Barrios (Argentina) |
| Featherweight | Eric Aiken (U.S.) | Scott Harrison (Scotland) |
| Super bantamweight | Israel Vazquez (Mexico) | Daniel Ponce de Leon (Mexico) |
| Bantamweight | Rafael Marquez (Mexico) | Jhonny Gonzalez (Mexico) |
| Super flyweight | Luis Alberto Perez (Nicaragua) | Fernando Montiel (Mexico) |
| Flyweight | Vic Darchinyan (Australia) | Omar Narvaez (Argentina) |
| Light flyweight | Ulises Solis (Mexico) | Hugo Cazares (Mexico) |
| Strawweight | Muhammad Rachman (Indonesia) | Ivan Calderon (Puerto Rico) |
