| Niederlage | 21-9 | Tito Ortiz  | KO (Punches) |  | Golden Boy MMA: Liddell vs Ortiz 3 | Nov 24, 2018 | 1 | 4:24 | Inglewood, California, United States |
| Niederlage | 21-8 | Rich Franklin | KO (punch) |  | UFC 115 | Jun 12, 2010 | 1 | 4:55 | Vancouver, Canada |
| Niederlage | 21-7 | Mauricio Rua  | TKO (punches) |  | UFC 97 | Apr 18, 2009 | 1 | 4:28 | Montreal, Quebec, Canada |
| Niederlage | 21-6 | Rashad Evans | KO (punch) |  | UFC 88 | Sep 06, 2008 | 2 | 1:51 | Atlanta, United States |
| Sieg | 21-5 | Wanderlei Silva | Decision (unanimous) |  | UFC 79 | Dec 29, 2007 | 3 | 5:00 | Las Vegas, United States |
| Niederlage | 20-5 | Keith Jardine | Decision (split) | | UFC 76 | Sep 22, 2007 | 3 | 5:00 | Anaheim, United States |
| Niederlage | 20-4 | Quinton Jackson | KO (punches) |  | UFC 71 | May 26, 2007 | 1 | 1:53 | Las Vegas, United States |
| Sieg | 20-3 | Tito Ortiz | TKO (punches) |  | UFC 66 | Dec 30, 2006 | 3 | 3:59 | Las Vegas, Nevada |
| Sieg | 19-3 | Renato Sobral | TKO (punches) |  | UFC 62 | Aug 26, 2006 | 1 | 1:35 | Las Vegas, United States |
| Sieg | 18-3 | Randy Couture | KO (punches) | | UFC 57 | Feb 04, 2006 | 2 | 1:28 | Las Vegas, United States |
| Sieg | 17-3 | Jeremy Horn | Submission |  | UFC 54 | Aug 20, 2005 | 4 | 2:46 | Las Vegas, United States |
| Sieg | 16-3 | Randy Couture | KO (punch) |  | UFC 52 | Apr 16, 2005 | 1 | 2:06 | Las Vegas, United States |
| Sieg | 15-3 | Vernon White | KO (punch) |  | UFC 49 | Aug 21, 2004 | 1 | 4:05 | Las Vegas, United States |
| Sieg | 14-3 | Tito Ortiz | TKO (punches) |  | UFC 47 | Apr 02, 2004 | 2 | 0:38 | Las Vegas, Nevada |
| Niederlage | 13-3 | Quinton Jackson | TKO (punches) |  | Pride Final Conflict 2003 | Nov 09, 2003 | 2 | 3:10 | Tokyo, Japan |
| Sieg | 13-2 | Alistair Overeem  | KO (punches) |  | Pride Total Elimination 2003 | Aug 10, 2003 | 1 | 3:09 | Saitama, Saitama, Japan  |
| Niederlage | 12-2 | Randy Couture | TKO (punches) |  | UFC 43 | Jun 06, 2003 | 3 | 2:39 | Las Vegas, United States |
| Sieg | 12-1 | Renato Sobral | TKO |  | UFC 40 | Nov 22, 2002 | 1 | 2:55 | Las Vegas, United States |
| Sieg | 11-1 | Vitor Belfort | Decision (unanimous) | | UFC 37.5 | Jun 22, 2002 | 3 | 5:00 | Las Vegas, United States |
| Sieg | 10-1 | Amar Suloev  | Decision (unanimous) |  | UFC 35 | Jan 11, 2002 | 3 | 5:00 | Connecticut, United States |
| Sieg | 9-1 | Murilo Bustamante | Decision (unanimous) | | UFC 33 | Sep 28, 2001 | 3 | 5:00 | Las Vegas, United States |
| Sieg | 8-1 | Guy Mezger | KO (punch) | | Pride 14 | May 27, 2001 | 2 | 0:21 | Yokohama, Japan |
| Sieg | 7-1 | Kevin Randleman | TKO (punches) | | UFC 31 | May 04, 2001 | 1 | 1:18 | Atlantic City, United States |
| Sieg | 6-1 | Jeff Monson  | Decision (unanimous) | | UFC 29 | Dec 06, 2000 | 3 | 5:00 | Tokyo, Japan |
| Sieg | 5-1 | Steve Heath | KO (head kick) | | IFC Warriors Challenge 9 | Jul 18, 2000 | 2 | 5:39 | Friant, California, United States |
| Sieg | 4-1 | Paul Jones | TKO (cut) | | UFC 22 | Sep 24, 1999 | 1 | 3:53 | Lake Charles, United States |
| Sieg | 3-1 | Kenneth Williams | Submission | | Neutral Grounds 11 | Mar 31, 1999 | 1 | 3:35 | Los Angeles, United States |
| Niederlage | 2-1 | Jeremy Horn | Technical submission | | UFC 19 | Mar 05, 1999 | 1 | 12:00 | Bay St. Louis, United States |
| Sieg | 2-0 | José Landi-Jons | Decision (unanimous) | | IVT 6 | Aug 23, 1998 | 1 | 30:00 | Sao Paulo, Brazil |
| Sieg | 1-0 | Noe Hernandez | Decision (unanimous) | | UFC 17 | May 15, 1998 | 1 | 12:00 | Mobile, United States |
