| Cancelled Bout | | Vicente Luque  | - |  | UFC Fight Night: Sandhagen vs Nurmagomedov | Aug 03, 2024 | - | - | Abu Dhabi  |
| Niederlage | 26-10 (2) | Robbie Lawler  | TKO (Retirement) |  | UFC 266: Volkanovski vs Ortega | Sep 25, 2021 | 3 | 0:44 | Las Vegas, Nevada, United States |
| NC | 26-9 (2) | Anderson Silva | NC (overturned) |  | UFC 183 | Jan 31, 2015 | 5 | 5:00 | Las Vegas, United States |
| Niederlage | 26-9 (1) | Georges St. Pierre  | Decision (unanimous) |  | UFC 158: St.Pierre vs Diaz | Mar 16, 2013 | 5 | 5:00 | Montreal, Canada |
| Niederlage | 26-8 (1) | Carlos Condit | Decision (unanimous) |  | UFC 143 | Feb 04, 2012 | 5 | 5:00 | Nevada, United States |
| Sieg | 26-7 (1) | B.J. Penn | Decision (unanimous) | | UFC 137 | Oct 29, 2011 | 3 | 5:00 | Las Vegas, Nevada, US |
| Sieg | 25-7 (1) | Paul Daley  | TKO (punches) |  | Strikeforce: Diaz vs. Daley | Apr 09, 2011 | 1 | 4:57 | San Diego, United States |
| Sieg | 24-7 (1) | Evangelista Santos | Submission (armbar) |  | Strikeforce: Diaz vs. Cyborg | Jan 29, 2011 | 2 | 4:50 | San Jose, United States |
| Sieg | 23-7 (1) | KJ Noons | Decision (unanimous) |  | Strikeforce: Diaz vs. Noons II | Oct 09, 2010 | 5 | 5:00 | San Jose, United States |
| Sieg | 22-7 (1) | Hayato Sakurai | Submission (armbar) |  | Dream 14 | May 29, 2010 | 1 | 3:54 | Saitama, Japan |
| Sieg | 21-7 (1) | Marius Žaromskis  | KO (punch) |  | Strikeforce: Miami | Jan 30, 2010 | 1 | 4:38 | Sunrise, United States |
| Sieg | 20-7 (1) | Scott Smith | Submission (rear-naked choke) |  | Strikeforce: Lawler vs. Shields | Jun 06, 2009 | 3 | 1:41 | St. Louis, United States |
| Sieg | 19-7 (1) | Frank Shamrock | TKO (punches) |  | Strikeforce: Shamrock vs. Diaz | Apr 11, 2009 | 2 | 3:57 | San Jose, United States |
| Sieg | 18-7 (1) | Thomas Denny | KO (punches) |  | EliteXC: Unfinished Business | Jul 26, 2008 | 2 | 0:30 | Stockton, United States |
| Sieg | 17-7 (1) | Muhsin Corbbrey | KO (punches) |  | EliteXC: Return of the King | Jun 14, 2008 | 3 | 3:59 | Honolulu, United States |
| Sieg | 16-7 (1) | Katsuya Inoue | TKO (corner stoppage) |  | Dream 3 | May 11, 2008 | 1 | 6:45 | Saitama, Japan |
| Niederlage | 15-7 (1) | KJ Noons | TKO (doctor stoppage) |  | EliteXC: Renegade | Nov 10, 2007 | 1 | 5:00 | Texas, United States |
| Sieg | 15-6 (1) | Mike Aina | Decision (split) |  | EliteXC: Uprising | Sep 15, 2007 | 3 | 5:00 | Honolulu, United States |
| NC | 14-6 (1) | Takanori Gomi  | NC (result overturned) |  | Pride 33 | Feb 24, 2007 | 2 | 1:46 | Nevada, United States |
| Sieg | 14-6 | Gleison Tibau | TKO (punches) | | UFC 65 | Nov 18, 2006 | 2 | 2:27 | Sacramento, United States |
| Sieg | 13-6 | Josh Neer | Submission (kimura) | | UFC 62 | Aug 26, 2006 | 3 | 1:42 | Nevada, United States |
| Sieg | 12-6 | Ray Steinbeiss | Decision (unanimous) | | ICFO 1 | May 13, 2006 | 3 | 5:00 | Stockton, United States |
| Niederlage | 11-6 | Sean Sherk | Decision (unanimous) |  | UFC 59 | Apr 15, 2006 | 3 | 5:00 | Anaheim, United States |
| Niederlage | 11-5 | Joe Riggs | Decision (unanimous) | | UFC 57 | Feb 04, 2006 | 3 | 5:00 | Nevada, United States |
| Niederlage | 11-4 | Diego Sanchez | Decision (unanimous) | | TUF 2 | Nov 05, 2005 | 3 | 5:00 | Nevada, United States |
| Sieg | 11-3 | Koji Oishi | KO (punches) | | UFC 53 | Jun 04, 2005 | 1 | 1:24 | Atlantic City, United States |
| Sieg | 10-3 | Drew Fickett | TKO (punches) | | UFC 51 | Feb 05, 2005 | 1 | 4:40 | Nevada, United States |
| Niederlage | 9-3 | Karo Parisyan | Decision (split) | | UFC 49 | Aug 21, 2004 | 3 | 5:00 | Nevada, United States |
| Sieg | 9-2 | Robbie Lawler | KO (punch) | | UFC 47 | Apr 02, 2004 | 2 | 1:31 | Las Vegas, Nevada, United States |
| Sieg | 8-2 | Jeremy Jackson | Submission (armbar) | | UFC 44 | Sep 26, 2003 | 3 | 2:04 | Nevada, United States |
| Sieg | 7-2 | Jeremy Jackson | KO (punches) | | IFC Warriors Challenge | Jul 19, 2003 | 1 | 4:33 | Lakeport, United States |
| Sieg | 6-2 | Joe Hurley | Submission (kimura) | | WEC 6 | Mar 27, 2003 | 1 | 1:55 | Lemoore, United States |
| Niederlage | 5-2 | Kuniyoshi Hironaka | Decision (split) | | Shooto: Year End Show | Dec 14, 2002 | 3 | 5:00 | Chiba, Chiba, Japan |
| Sieg | 5-1 | Harris Sarmiento | TKO (corner stoppage) | | Warriors Quest 8 | Oct 24, 2002 | 2 | 1:47 | Honolulu, United States |
| Niederlage | 4-1 | Jeremy Jackson | TKO (punches) | | UA 4: King of the Mountain | Sep 28, 2002 | 1 | 0:49 | Auberry, United States |
| Sieg | 4-0 | Adam Lynn | Submission (armbar) | | UA 4: King of the Mountain | Sep 28, 2002 | 1 | 2:51 | Auberry, United States |
| Sieg | 3-0 | Blaine Tyler | TKO (punches) | | UA 4: King of the Mountain | Sep 28, 2002 | 2 | 2:01 | Auberry, United States |
| Sieg | 2-0 | Chris Lytle | Decision (split) | | IFC W Challenge 17 | Jul 12, 2002 | 3 | 5:00 | Porterville, United States |
| Sieg | 1-0 | Mike Wick | Submission (triangle choke) | | IFC W Challenge 15 | Aug 31, 2001 | 1 | 3:43 | Oroville, United States |
