Im Joo-hwan made his television acting debut in the 2004 SBS series Magic. In 2009, he became part of the main cast of the MBC drama Tamra, the Island, which won him Best New Actor at the 17th Korea Culture and Entertainment Awards. In 2013, he led the SBS daily series Watch Out for Fools, which earned him the New Star Award at the SBS Drama Awards. In 2015, he acted alongside Park Bo-young and Jo Jung-seok in tvN’s Oh My Ghostess. In 2019, he was nominated for an Excellence Award at the MBC Drama Awards for his performance in the historical series Different Dreams. In 2020, he starred in the MBC dramas The Game: Towards Zero and The Spies Who Loved Me, which gave him an Excellence Award at the MBC Drama Awards.

Im Joo-hwan enlisted for his mandatory military service in May 2011. He was hospitalized for heart problems after fainting while undergoing basic military training. He completed his conscription in February 2013 despite being given an option to be discharged early.