| Niederlage | 19-11 | Lyoto Machida  | KO (jumping front kick) |  | UFC 129 | Apr 30, 2011 | 2 | 1:02 | Toronto, Canada |
| Sieg | 19-10 | James Toney | Submission |  | UFC 118 | Aug 28, 2010 | 1 | 3:19 | Boston, United States |
| Sieg | 18-10 | Mark Coleman  | Submission (rear-naked choke) |  | UFC 109 | Feb 06, 2010 | 2 | 1:09 | Las Vegas, Nevada, U.S. |
| Sieg | 17-10 | Brandon Vera | Decision (unanimous) |  | UFC 105 | Nov 14, 2009 | 3 | 5:00 | Manchester, England |
| Niederlage | 16-10 | Antonio Rodrigo Nogueira | Decision (unanimous) |  | UFC 102 | Aug 29, 2009 | 3 | 5:00 | Portland, United States |
| Niederlage | 16-9 | Brock Lesnar | TKO (punches) |  | UFC 91 | Nov 15, 2008 | 2 | 3:07 | Las Vegas, United States |
| Sieg | 16-8 | Gabriel Gonzaga | TKO (punches) |  | UFC 74 | Aug 25, 2007 | 3 | 1:37 | Las Vegas, United States |
| Sieg | 15-8 | Tim Sylvia | Decision (unanimous) | | UFC 68 | Mar 03, 2007 | 5 | 5:00 | Columbus, Ohio, United States |
| Niederlage | 14-8 | Chuck Liddell | KO (punches) | | UFC 57 | Feb 04, 2006 | 2 | 1:28 | Las Vegas, United States |
| Sieg | 14-7 | Mike Van Arsdale | Submission (anaconda choke) |  | UFC 54 | Aug 20, 2005 | 3 | 0:52 | Las Vegas, United States |
| Niederlage | 13-7 | Chuck Liddell | KO (punch) |  | UFC 52 | Apr 16, 2005 | 1 | 2:06 | Las Vegas, United States |
| Sieg | 13-6 | Vitor Belfort | TKO (doctor stoppage) |  | UFC 49 | Aug 21, 2004 | 3 | 5:00 | Las Vegas, United States |
| Niederlage | 12-6 | Vitor Belfort | TKO (cut) |  | UFC 46 | Jan 31, 2004 | 1 | 0:49 | Las Vegas, United States |
| Sieg | 12-5 | Tito Ortiz | Decision (unanimous) |  | UFC 44 | Sep 26, 2003 | 5 | 5:00 | Las Vegas, Nevada |
| Sieg | 11-5 | Chuck Liddell | TKO (punches) |  | UFC 43 | Jun 06, 2003 | 3 | 2:39 | Las Vegas, United States |
| Niederlage | 10-5 | Ricco Rodriguez | Submission (elbow) | | UFC 39 | Sep 27, 2002 | 5 | 3:04 | Montville, United States |
| Niederlage | 10-4 | Josh Barnett | TKO (punches) | | UFC 36 | Mar 22, 2002 | 2 | 4:35 | Las Vegas, United States |
| Sieg | 10-3 | Pedro Rizzo | KO (strikes) | | UFC 34 | Nov 02, 2001 | 3 | 1:38 | Las Vegas, United States |
| Sieg | 9-3 | Pedro Rizzo | Decision (unanimous) | | UFC 31 | May 04, 2001 | 5 | 5:00 | Atlantic City, United States |
| Sieg | 8-3 | Tsuyoshi Kohsaka  | Decision (unanimous) | | Rings: King of Kings 2000 Final | Feb 24, 2001 | 2 | 5:00 | Tokyo, Japan |
| Niederlage | 7-3 | Valentijn Overeem  | Submission | | Rings: King of Kings 2000 Final | Feb 24, 2001 | 1 | 0:56 | Tokyo, Japan |
| Sieg | 7-2 | Kevin Randleman | TKO (strikes) | | UFC 28 | Nov 17, 2000 | 3 | 4:13 | Atlantic City, United States |
| Sieg | 6-2 | Ryushi Yanagisawa | Decision (majority) | | Rings: King of Kings 2000 | Oct 09, 2000 | 2 | 5:00 | Tokyo, Japan |
| Sieg | 5-2 | Jeremy Horn | Decision (unanimous) | | Rings: King of Kings 2000 | Oct 09, 2000 | 3 | 5:00 | Tokyo, Japan |
| Niederlage | 4-2 | Mikhail Ilyukhin  | Submission (kimura) | | Rings: Rise 1st | Mar 20, 1999 | 1 | 7:43 | Tokyo, Japan |
| Niederlage | 4-1 | Enson Inoue | Submission (armbar) | | Vale Tudo Japan 1998 | Oct 25, 1998 | 1 | 1:39 | Japan |
| Sieg | 4-0 | Maurice Smith | Decision (majority) | | UFC Japan | Dec 21, 1997 | 1 | 21:00 | Yokohama, Kanagawa, Japan |
| Sieg | 3-0 | Vitor Belfort | TKO (punches) | | UFC 15 | Oct 17, 1997 | 1 | 8:16 | Bay St. Louis, United States |
| Sieg | 2-0 | Steven Graham | TKO (punches) | | UFC 13 | May 30, 1997 | 1 | 3:13 | Augusta, United States |
| Sieg | 1-0 | Tony Halme | Submission | | UFC 13 | May 30, 1997 | 1 | 1:00 | Augusta, United States |
