The group's intense popularity, nicknamed "Rollermania", took off shortly afterwards. He was with the band until 1978, at which time he left to pursue a career as a solo artist, releasing a series of solo albums which saw modest success, primarily in Germany and Japan.
In a 2009 interview with Scottish Sunday newspaper Scotland on Sunday, he admitted that he had a sexual encounter whilst on the influence of Methaqualone (better known by the brand name Quaalude), with the group's manager and primary spokesperson, Tam Paton.
In was in 1988 and 1989 McKeown worked with Dieter Bohlen. The result of their partnership was the album It's A Game. In 1990, he participated in the UK heats of the Eurovision Song Contest with the song "Ball and Chain", which placed fifth.
It was during his televised rehab stint that he came out as Bisexual, as well as having been date raped at age 17, an incident which left him permanently scarred, and unable to cope with his shame of experiencing an involuntary orgasm during the assault.
On 3 February 2006, he was acquitted of cocaine dealing. He suggested that he would sue the Metropolitan Police for £160,000 in earnings he lost from an overseas tour in the United States that was cancelled as a result of the proceedings.
In a 2006 interview with Scotland on Sunday he said about the ordeal, "I'm considering taking a civil action against the police and in fact I'm consulting with my lawyers now. The charge was terrible and whimsical and I've had to rely on members of the public seeing through the flimsy, circumstantial evidence, I've been through months of hell. I've had to sign on at the police station twice a day and the police took away my passport so I lost £160,000 of work abroad."
- "Former Bay City Rollers front man, Les McKeown, is ready finally to leave the past behind". The Scotsman. 2009-02-13. Retrieved 2015-08-27.
- "Les McKeown rehab pt 4 of 4". YouTube. 2011-04-16. Retrieved 2015-08-27.
- "UK | England | London | Singer denies being drug dealer". BBC News. 2006-01-30. Retrieved 2015-08-27.
- "Roller Les in threat to sue police". The Scotsman. 2006-02-04. Retrieved 2015-08-27.
- Stambler, Irwin, Encyclopedia of Pop, Rock & Soul. 1974. St. Martin's Press, Inc., New York, N.Y. ISBN 0-312-02573-4
- Shang-a-lang: Life as an International Pop Idol Les McKeown, Lynne Elliott, Irvine Welsh, 2003 ISBN 1-84018-651-8