[2] Lee began his career on stage in 1963, in the play Of Mice and Men, and has appeared in numerous works of Korean theatre, film and television.

In 1977, with his fellow actor Jeon Moo-song, Lee performed in play Crown Prince Hamyeol (an adaptation of Hamlet) at La MaMa in New York City, which marked the first time a Korean theatre troupe had traveled outside Korea.

Lee's fellow classmate included Shin Gu, Jeon Moo-song, Ban Hyo-jeong (who did not graduate), and playwright Yoon Dae-seong.

[10] In 1963, Lee made his stage debut as Lenny Small in John Steinbeck's Of Mice and Men at the Myeongdong National Theater.

[13] In 1975, Lee with his fellow actor Jeon Moo-song and playwright Oh Taeseok joined National Theater Company of Korea (NTCK).

[14] In 1977, Lee with Jeon Moo-song and Oh Taeseok, joined Dongnang Repertory Theater Company's World Tour Return Commemorative Performance.

Dongrang Repertory theater company led by CEO Yoo Deok-hyung (president of Seoul Institute of the Arts at that time) toured the world for about three months from March 9 to May 30 19777, sponsored by Joongang Ilbo, Dongyang Broadcasting, and the American Headquarter of International Theatre Institute (ITI), co-hosted by the Rockefeller Foundation in the United States).

The repertoire of this world tour theater performance is "Tae (Life Cord)" and Crown Prince Hamyeol (directed by Ahn Min-su, an adaptation of Shakespeare's original Hamlet).

[17] Lee was nicknamed "The Eternal Watchman of the Theater World" because he stayed in the theatre even when his seniors and colleagues left for television dramas and movies.

[8] Lee wanted to be financially independent by only do plays, but due to circumstances after marriage with children, since 1980s he was forced to also do radio, television dramas and films.

[18] In 2005, Lee performed in the play "The Story of Two Knights Moving Around the World" by Betsuyaku Minoru, one of the leading playwrights in modern Japan.

This was written by Lee Man-hee as tribute to him and the time of its premiere in 2007, it received a great response from the middle-aged audience with his warm and pleasant gaze toward the silver age and delicious lines.

The play is centered on 'Wan-gyu' (Lee Ho-jae), who lives and runs a business alone in a plastic house office after divorce, and 'Chun-san' (Nam Myeong-ryeol), a friend.