At the 2004 Summer Olympics in Athens, Cho qualified again for the men's 1500 m freestyle by posting a FINA B-standard entry time of 15:19.49 from the Summer Universiade in Daegu. He challenged seven other swimmers on the third heat, including top medal favorite David Davies of Great Britain. Cho rounded out the field to last place by a 13.38-second margin behind Russia's Alexey Filipets in 15:43.43. Cho failed to advance into the final, as he placed twenty-fifth overall in the preliminaries.