In November 1993, as a junior at Shinil High School in Seoul, South Korea, Cho was selected as a member of the South Korea junior national baseball team and competed in the annual friendly baseball series against the Japan junior national baseball team in Okinawa, Japan.
In 1994, Cho started his collegiate career playing for Yonsei University. Regarded as the nation's top catching prospect in college baseball, he regularly participated in international events during his four years at the college.
After the 1999 season, All-Star veteran catcher Kim Dong-soo became a free agent and signed with the Samsung Lions for the 2000 season. Upon Kim Dong-soo's departure through free agency to the Samsung Lions, Cho earned the full-time position behind the plate for the Twins in the 2000 season.
In 2000, his first season as the full-time catcher for the Twins, Cho struggled at the plate, batting .225 with 5 home runs but exhibited strong defensive skills, leading the league in caught-stealing percentage, as he threw out 24 of 50 runners.
In 2003, Cho hit a career-high 19 home runs with a 257 batting average and 58 RBIs, playing in a career-high 132 games as the club's full-time catcher.
In 2007, Cho had his most offensively productive season when he posted career-highs in batting (.282), hits (118), RBI (73), runs (44) and doubles (24) in 124 games.
During a televised pennant game in August 2009, Cho and one of his teammate pitcher Shim Soo-chang arguing on the mound was caught on camera. The next day, Cho and Shim were both sent to the LG Twins minor league system.