Ortiz began his martial arts career as a wrestler in his sophomore year of high school. Under coach Paul Herrera, Ortiz came fourth in the state high school championships as a senior. Following high school, Ortiz continued his wrestling career winning a California state junior college title for Golden West College. Following his stint at Golden West, Ortiz wrestled at Cal State Bakersfield. Ortiz trained with future NCAA and world champion Stephen Neal.
His mixed martial arts debut was at UFC 13 in 1997. Still in college, Ortiz competed as an amateur for no prize money or contracts. He beat Wes Albittron on the tournament's first round by referee stoppage, but lost in the next round to Guy Mezger.
In 1999 Ortiz fought Frank Shamrock for the UFC Middleweight (200 pound) title at UFC 22, losing via submission due to strikes. Following the victory, Shamrock retired and vacated the championship. The Middleweight title was renamed the Light Heavyweight title and Ortiz was chosen, along with Wanderlei Silva, as a top contender. Ortiz won the title fight at UFC 25 via unanimous decision. He went on to defend the belt five times in the following three years, defeating Yuki Kondo, Evan Tanner, Elvis Sinosic, Vladimir Matyushenko and Lion's Den head Ken Shamrock.
Ortiz next fought the new Interim Light Heavyweight Champion Randy Couture, who had defeated Liddell for the interim title, at UFC 43 in September 2003. Couture defeated Ortiz via unanimous decision, adding insult to injury by literally spanking the younger fighter in the ring.
Following his loss to Randy Couture, Ortiz faced Chuck Liddell at UFC 47. Ortiz lost by second round knockout. After six months off, Ortiz returned and took a unanimous decision victory over newcomer Patrick Cote at UFC 50, and a split decision over Vitor Belfort at UFC 51. In February 2005, Ortiz began time away from the UFC and was offered deals with several promotions, including PRIDE Fighting Championships and the Don King-backed World Fighting Alliance, but none came to fruition.
Ortiz returned to the UFC on April 15th, 2006, at UFC 59 against Ultimate Fighter 1 winner Forrest Griffin. Ortiz won via split decision. Tito then went on to defeat Ken Shamrock twice in lopsided fights which earned him a shot at Liddell again. Liddell continually avoided Tito's takedown attempts and pummelled Ortiz while standing.
Tito Ortiz then fought to draw with Rashad Evans at UFC 83 in what many considered an uneventful fight.
Tito is big for a light heaveyweight. His game relies soley on his takedowns to set up a vicious ground and pound. Tito is still extremely dangerous against opponents with suspect wrestling and poor takedown defense.