Lim competed for the South Korean swimming team in the men's 100 m freestyle at the 2008 Summer Olympics in Beijing. Leading up to the Games, he finished outside the top-eight final time in 50.82 to set a new national mark and register under the FINA B-cut (50.95) by 0.13 of a second at the 2007 Summer Universiade in Bangkok, Thailand. Coming from sixth at the halfway turn in heat three, Lim edged out the Uzbek swimmer Petr Romashkin by just 0.03 of a second on the final stretch to hit the wall with a fifth-place time in 51.80, almost a second off his entry mark. Lim failed to advance into the semifinals, as he placed fifty-fourth out of 64 swimmers in the prelims.