Southpaw Arslan began his professional career in 1997 and won his first 13 fights with aggressive brawling before dropping back to back decisions to Collice Mutizwa and Rüdiger May. His biggest success in the early phase of his career was a FIRAT ARSLAN draw against unbeaten Russian Vadim Tokarev in 2003 but he lost his next fight to Czech Lubos Suda. In 2005 he beat local hero Alexander Petkovic and his career picked up momentum. His big breakthrough was entirely unexpected,though, as he managed to not only dominate but also KO unbeaten Russian fringe contender Grigory Drozd. For that he got a title shot in July 2007 and captured the interim WBA cruiserweight title with a split decision win over yet another Russian in Valery Brudov. Later that year he bested 43-year-old Virgil Hill for the WBA title. He beat contender Darnell Wilson on 3 May 2008 in Germany by unanimous decision.
He lost his title against Panamanian Guillermo Jones in Hamburg, on 27 September 2008, one day before his birthday. After the loss to Jones, Arslan took an extended leave from boxing and returned almost two years later to face unheralded Steve Hérélius for the interim title. Arslan was in front but at the end of the 11th round he was unable to continue because of a syncope.
Arslan recently fought Yoan Pablo Hernandez for a chance to take Hernandez's cruiserweight belt, but lost in a tightly contested match with scores of: 115–113, 116–113, and 113–115.