Brett McDermott has five losses against five opponents on his MMA record. For a list of McDermott's best fights, refer to "Best fights of Brett McDermott".
On February 24, 2017 Brett McDermott faced off against Liam McGeary in a heavyweight bout at age 38. He was coming in with a record of 7-5 (6), and McGeary was 34 years old and with a record of 11-1 (10). McDermott lost the fight via 2nd-round TKO.
On July 9, 2016 Brett McDermott faced off against Kenneth Bergh in a heavyweight bout at age 37. He was coming in with a record of 6-4 (5). McDermott lost the fight via 1st-round submission.
On December 29, 2015 Brett McDermott faced off against Muhammed Lawal in a heavyweight bout at age 37. He was coming in with a record of 5-3 (4), and Lawal was 34 years old and with a record of 16-4 (11). McDermott lost the fight via 1st-round KO.
On April 25, 2015 Brett McDermott fought Marcin Lazarz in a light-heavyweight title fight for the BAMMA World Championship title. McDermott was 36 years old and with a record of 4-2 (3). McDermott lost the fight via 3-round unanimous decision.
On March 9, 2013 Brett McDermott faced off against Thomas Denham in a light-heavyweight bout at age 34. He was coming in with a record of 0-1 (0). McDermott lost the fight via 2nd-round submission.
