The first success of the tall right arm Bute was the second place in the bantamweight title at the European Championships in the age class of the Cadet (U -17) in 1996 in Aosta. In 1998 he took part in the Junior World Championships in Buenos Aires and took there a third place in the welterweight division.
The Amateur Senior World Championships in 1999 in Houston, he finished in third place. At the World Championships of 2001 in Belfast middleweight he managed a medal placement. At the European Championships in 2002 in Perm he could defeat Gaidarbek Gaidarbekow, but lost in the quarter- final against Hungary Károly Balzsay.
In 2003, he won with a final victory over Mathias Kempe Chemistry Cup, failed at the World Championships in Bangkok, however, in the quarterfinals with a knockout loss at the Kazakh Gennady Golovkin.
Even in 2003, was signed Lucian Bute of InterBox in Canada. He won with an action-packed style of attack his previous fights, including against former world champion Dingaan Thobela and the Egyptian world title challenger Kabary Saleem, the Joe Calzaghe was on the ground and with this went by. In January 2007, he beat Sergei Tatewosjan who had Armand Krajnc and Rudy Markussen defeated prematurely, and in June 2007 the Cameroonian Sakio Bika in an IBF eliminator of the Association respectively on points.
On 19 October 2007 Bute finally met as the official challenger to the IBF world champion Alejandro Berrio and secured the title by technical knockout in the eleventh round. He defended the title against the then former middleweight world champion William Joppy and the Mexicans Librado Andrade. In the fight against Andrade Although he scored in the tenth round of a precipitate which had, however, in the twelfth round a few seconds before the end of the fight, even after several impact hits to the ground and had been hit hard.
Because of the controversial end of this fight, there were demands for an immediate rematch, but Bute defended the IBF title first in March 2009 by a premature victory against Colombian Fulgencio Zúñiga. Andrade qualified by a point win against Ukrainian Vitaly Zypko in an eliminator directly for another title fight against Bute, which was then scheduled for November 28, 2009 in Quebec City. Bute could this rematch by a whacked clearly decide for themselves in round four.
The fifth defense of the IBF title denied Bute 17 April 2010 against Colombian Edison Miranda. Miranda, who had usually proven by then as beating strongly, but boxtechnisch limited in his career and was always inferior to superior opponents, went into the third round after a left uppercut Butes to the ground and recovered from this damage with no more, so that the fight is abandoned soon after Bute and was declared the winner by technical knockout.
On 15 October 2010 he defended his title by knockout in round nine on the U.S. American Jesse Brinkley. In 2011, Bute completed three title defenses. First, he defeated in March, the Northern Irishman Brian Magee prematurely. Then fought Bute in July for only the second time in his career in his native Romania, where she won against the previously unbeaten mandatory challenger Jean -Paul Mendy by knockout in round four. This was followed in November, a points victory against the already 42 -year-old Jamaican Glen Johnson.
Additional voluntary title defense Bute occurred on May 26, 2012 in Nottingham, the hometown of his opponent Carl Froch. He defeated the British by technical whacked in the fifth round, and thus lost the IBF title after 4.5 years and a total of nine title defenses. In January 2014, he also lost on points against Jean Pascal.