Jeon-Sik Yoo has earned high praise since winning the Hanyang University Competition, the Yeonsei University Competition, and the Incheon Newspaper Music Competition in 1968. After graduating from Hanyang University in 1972, he joined the National Symphony Orchestra as a principal and assistant principal in 1975. In 1979, he began studying at the G. Verdi National Music Conservatory in Milano, Italy. While there, he toured sixteen cities in Switzerland and Italy as a member of Pomeriggio Musicali and a leader of G. Verdi Trombone Ensemble. He also performed in many European venues as soloist and principal trombonist with the Milano Symphony Band in 1981.
He was principal trombonist with the KBS Symphony Orchestra from 1983 to 2000. Performances as a concert soloist with that group opened up chances to perform with many orchestras and wind ensembles in Korea.
Jeon-Sik has been involved in the musical scenes in the United States, Japan, Taiwan, and China. In November 2002, he was invited to teach masterclasses and conduct a wind orchestra concert at Cal State Fullerton. Since 2006, he has been performing every year at the Korea, China, and Japan International Exchange concerts program hosted by Nakasaki University. Also, he served as a jury member at the Taiwan International Music Festival in 2007 and Shanghai International Music Festival in 2011 and 2012.
Jeon-Sik founded the Haneum Trombone Ensemble in 1984. He has appointed as a chairman of the First Korean International Wind Band Festival by the Ministry of Culture and Tourism. In addition, he was invited to serve as a jury member at the Coups de vents Du Concours International de Composition Final in 2013.
Currently, Jeon-Sik is a professor at the College of Music of Hanyang University. He is a leader of Haneum Trombone Ensemble, a chairman of the board at the Korean Wind Music Association Director, and a promotion chairman for the Korean International Wind Music Band Festival.