|Representing South Korea|
|1998 Bangkok||Mixed doubles|
|Revised Romanization||I Dong-su|
Lee competed for Korea in badminton at the 2004 Summer Olympics in men's doubles with partner Yoo Yong-sung. They defeated José Antonio Crespo and Sergio Llopis of Spain in the first round and Luluk Hadiyanto and Alvent Yulianto of Indonesia in the second. In the quarterfinals, Lee and Yoo beat Choong Tan Fook and Lee Wan Wah of Malaysia 11-15, 15-11, 15-9. They won the semifinal against Jens Eriksen and Martin Lundgaard Hansen of Denmark 9-15, 15-5, 15-3 but lost the final to fellow Koreans Kim Dong-moon and Ha Tae-kwon 15-11, 15-4 to finish with the silver medal.