In 1969 he founded Gasolin' with Franz Beckerlee and Willi Jønsson (later joined by drummer Søren Berlev) and by their third album in 1973 they had grown to be the leading danish rock band. The bands characteristics were Franz Beckerlee's Hendrix-inspired guitar licks and the bands easy to sing along with blend of streetwise and social-romantic lyrics, that even when credited to the band and lyricist Mogens Mogensen clearly was masterminded by Larsen. The bands national stardom continued until growing tensions between Larsen and Beckerlee led to Gasolin' disbanding August 21st, 1978.
During the Gasolin' era Larsen also had side-projects and solo-project. In 1973 he released his first soloalbum, the folkish singer-songwriter album "Værsgo", that has continued to be popular and three decades after it's release was officially marked as part of Kulturkanonen (a list of essential Danish cultural heritage). In 1977 he release an english languaged album recorded in the US in an attempt to achieve the international breakthrough that had failed for Gasolin' a couple of years earlier, but the album failed too. Occationally he released and performed with side-projects Sylvester's Jukebox and Starfuckers (2). He also wrote the 1978 hit "Se venedig og dø" for Lone Kellermann.
Post Gasolin' after a danish languaged pop album, Larsen did a third attempt for international audience with the group Kim Larsen And Jungledreams, this time in a disco/synthpop style. After two albums that proved to fail as well, and Larsen since then stuck to the danish language and a national focus.
That proved instantly succesful. His next album, the 1983 "Midt om natten", sold more than half a million copies. The album was also the soundtrack for his same-titled box office hit movie, which he wrote and co-stared and gave him an "Robert" actors award.
Throughout the 80's with his band Kim Larsen & Bellami he remained at the top of the charts and maintained his status as a national poet and top-selling artist, however by the turn of the decade his popularity has gradually decreased. With his next band, Kim Larsen & Kjukken he has turned his repertoire towards schlagers and lost appeal with the younger half.
Larsens remains one of the most popular artists in Danish popular music history. In total as solo artists Kim Larsen has sold approximately 3 million records, equivalent of 1 record for every 2 danes.