Mustasch was formed in the autumn of 1998 in Gothenburg, but instead of adopting the Gothenburg sound came out with a hard rock and heavy metal sound. Ralf Gyllenhammar was formerly of B-Thong. Members had played together in Grindstone. The band released a 1999 demo. Daredevil Records invited the band to participate in the Burn The Street Volume One Compilation vinyl featuring Mustasch, The Awesome Machine, We and Blacktop. The group appeared in a Toyota commercial. The 2001 EP was called The True Sound Of The New West. The band’s EMI imprint Majesty also released a full-length called Above All. The band opened for Motörhead supporting RatSafari.
Recorded in Stockholm, the band’s debut album was RatSafari and released by major label EMI. By 2006, the band was on the Swedish independent Regain Records and had an EP called Parasite! Latest Version Of The Truth was accompanied by a concept video for the song Double Nature. Hannes Hansson left to focus on his job and family. Mustasch made its touring guitarist, David Johannesson (ex-Sparzanza), a permanent member. The 2008 DVD In the Night - Live In Gothenburg was obviously filmed in the city. Still on the label, the band had an independent and self-titled record in 2009. Drummer Mats "Dojan" Hansson left the Swedish hard rockers due to his “chronic muscle ruptures" and arthritis thus making it impossible for him to continue. Danne McKenzie who had previously deputized for Dojan replaced him. Danne McKenzie played on the self-titled record. With Regain winding down the band next switched to another Swedish label, the local Gain Music Entertainment, which also housed Crashdïet and Avatar. The band lost drummer Danne McKenzie at the very end of 2011 due to, you guessed it, personal differences. The song The Challenger, from Sounds Like Hell, Looks Like Heaven, was a charting single for the band. Ralf Gyllenhammar entered the Melodifestivalen competition in 2013 hoping to represent Sweden at the Eurovision Song Contest with the track Bed On Fire. Robban Bäck joined in late 2015. The band founded its own imprint, Tritonus Records. A Final Warning - Chapter One was a 2021 EP. The band was commemorating the 20th anniversary of its debut album by issuing its 2021 album as two chapters.
The band claimed the monicker was chosen because many of the members’ musical idols sported ‘mustaches.’ It named Freddie Mercury of Queen, Jon Lord of Deep Purple and Tony Iommi of Black Sabbath as such people.