[2] He played for the Los Angeles Dodgers, Texas Rangers, San Diego Padres, New York Mets, Philadelphia Phillies, New York Yankees, and Pittsburgh Pirates of Major League Baseball (MLB), the Orix Buffaloes of Nippon Professional Baseball (NPB), and the Hanwha Eagles of the KBO League.

He posted a 2.76 ERA in helping South Korea earn the silver medal at the Asian Baseball Championship in 1993.

Park was a sophomore at Hanyang University, Seoul in 1994 when he was signed by the Los Angeles Dodgers as an amateur free agent.

In 1993, Park Chan-ho attended Hanyang University in Seoul, and in the same year at the Asian Cup held in Perth, Australia, Chinese team hitters Chen Qingguo and Tong Qinghui hit a home run from him.

After the season, he led the South Korean national team to the gold medal in the Asian Games, beating Japan in the final match.

On April 23, 1999, he became the only pitcher in the history of baseball to allow two grand slams in the same inning and to the same player, Fernando Tatís of the St. Louis Cardinals.

There are two more pitchers in the history of baseball who allowed two grand slams in the same game — Jack Morris, and more recently, Brandon Backe — but to different hitters in different innings.

On June 5, 1999, Park was involved in an on-field brawl at Dodger Stadium with Anaheim Angels pitcher Tim Belcher.

He was 15–11 with a 3.50 ERA during the season and was selected to appear in the 2001 Major League Baseball All-Star Game, where he pitched one inning, allowed a home run to Cal Ripken Jr. and was charged with the loss.

In the 2006 season, Park was reunited with his former Texas Rangers teammate and friend Chris Young, who was traded to the Padres in exchange for Akinori Otsuka.

Park accepted blood transfusions, that came, in part, from Jake Peavy's wife Katie and Kelly Calabrese, the Padres' team massage therapist.

On October 3, 2006, Park made his first career postseason appearance in Game 1 of the National League Division Series against the St. Louis Cardinals as a reliever.

On February 8, 2007, the Yonhap news agency and New York Daily News reported that Park had signed a one-year, $3 million contract with the New York Mets and would report to the Mets' spring training facility in Port St. Lucie, Florida to compete for a starting rotation spot.

[15] On November 8, 2007, Park accepted an offer from his original team, the Los Angeles Dodgers, to attend spring training as a non-roster invitee.

Despite being considered a long shot for the fifth starter's role, Park pitched very well, but was ultimately passed over for right-hander Esteban Loaiza.

Faced with the problem of a fatigued and depleted pitching staff three games later, the Dodgers purchased Park's minor league contract on April 2, 2008.

[19] In addition to making history, he had a decent outing, with nine strikeouts in five innings pitched, although this was overshadowed when he gave up a solo home run to Cleveland Indians pitcher CC Sabathia.

Jonathan Broxton was promoted to the closer role and Park and Hong-Chih Kuo to the setup man platoon.

[20] On March 31, Phillies GM Rubén Amaro Jr. announced that Chan Ho Park had won the fifth starter job.

[23][24] Chan Ho Park decided to play for the Yankees after rejecting an offer of around $3 million per year from the Philadelphia Phillies.

On December 20, 2011, Park announced that he would guarantee a minimum of $35.5k (₩40 million) of his salary to fund the development of amateur baseball in South Korea.

His contract bonus has potential earnings at up to $550,000 (₩600 million) in which Park would donate 100% of this salary to fund efforts to build amateur baseball with youth in the country.

In the Asia Round games against Taiwan and Japan, Park made appearances as a closing pitcher, shutting out the opposing lineups.

His performance made San Diego Padres' manager Bruce Bochy believe that Park can be used as an effective reliever as well as a starter.

In his prime, Chan Ho was essentially a power pitcher, his biggest weapon being a four-seam fastball sitting in mid-90s (topped out at 100 mph[31]).

Park's 2008 comeback season was marked with a return to complete health for the first time in years, allowing him to combine his crafty veteran style with a renewed ability to pitch effective fastballs in low to mid-90s mph.

In spring 2009, Ri-hye released a best-selling cookbook in South Korea whose proceeds went to children's charities on behalf of the Chan Ho Park Dream Foundation.