He performed at music festivals and concerts in Europe, in Germany, Great Britain, Spain, Portugal, Czechia, Slovakia, Austria, Switzerland, Italy, Belgium, the Netherlands, Hungary, France, Greece or Liechtenstein.

[21] After being the artistic director of the LiGiTa (Liechtensteinische Gitarren Tage) over 14 years, Koudelak start to work at the same position in Bangkok for the Asia International Guitar Festival in 2001.

[28] Furthermore, he was included in February 2013, as a member of the Honour Committee for the Tirana International Guitar Festival & Competition (Albania).

[31] A concert tour in Asia followed from June until December 2013 with confirmed dates in Bangkok, Jakarta, Tokyo, Kathmandu and Singapore.

Koudelak is a prize winner of the guitar competition "Fundación Jacinto e Inocencio Guerrero" in Madrid,[citation needed] and received for his artistic performances the Appreciation Award from the Ministry of Education, Arts and Culture.

[citation needed] In August 2012, Koudelak was appointed as chairman of the steering committee of the Indonesia International Guitar Festival & Competition.

He recorded works by Johann Sebastian Bach, Robert de Visée, Dionisio Aguado, Anton Diabelli, Lennox Berkeley, Michael Buchrainer, Antonio José, Maurice Ravel, Isaac Albéniz, Enrique Granados, Joaquin Rodrigo, Joaquin Turina, Carlo Domeniconi, Manuel Maria Ponce, Heitor Villa-Lobos, Roland Dyens, Francisco Tarrega, Jon Lord, David Coverdale, Glenn Hughes, Leo Brouwer, Eduardo Martin, Edin Solis and others.

[23][40] The DVD Leon Koudelak: Live in Seoul, in a remastered "10th Year's Anniversary Edition", was released by Tyrolis Classic in February 2011.

[citation needed] In 2017 the DVD "Live in Korea 2016" was published with works by Johann Sebastian Bach, Eduardo Martin, Enrique Granados, Heitor Villa-Lobos, Carlo Domeniconi, Thomas James Pegram and Cees Hartog.