The card was headlined by two Title Bouts, a Middleweight Championship Bout between Tito Ortiz and Evan Tanner, and the first UFC Bantamweight Championship Bout between Jens Pulver and Caol Uno. Following UFC 31, Bantamweight was renamed "Lightweight" under the new Unified Rules of Combat, defined by the Nevada State Athletic Commission. Bantamweight fighters would not again appear in the UFC until after the UFC-WEC merger in 2011. The event featured the first UFC appearances of Phil Baroni, Sean Sherk and Elvis Sinosic.