Lee graduated from Korea University in 1993,[2] and after graduation he joined the LG Twins.[2] Beginning his career as a starting pitcher, his best two years were 1994 and 1995, when he won 18 and 20 games, respectively. His record of 20-5 with a 2.01 ERA, 12 complete games, and 142 strikeouts in 1995 earned him a KBO League Golden Glove Award.
He converted to a closer following the 1995 season.
Lee was posted in 1998, but became the first player whose Korean team rejected the bid for the right to negotiate with him.[3] Lee eventually did make it to the Major Leagues, pitching in nine games for the Boston Red Sox in the 2000 MLB season, recording no decisions and a 3.09 ERA in 11.2 innings pitched.
Lee was at one time the highest-paid player in the KBO after he signed a 600-million-won contract in his second stint with the LG Twins in 2003.[4]
Since his retirement, he has coached in the KBO Futures League and the KBO.