"We have waited very long and worked very hard to launch Pokemon Go in South Korea," said Lim Jae Boem, chief executive of Pokemon Korea.
The game was jointly developed by Nintendo and Niantic Inc.
Pokemon Go relies on Google Maps to work. But in most of South Korea those functions have been limited by the government, which is technically still at war with North Korea, for national security reasons.
Neither Niantic nor Pokemon Korea specified how they managed to work around the Google Maps challenge.
"We used various publicly accessible data sources," said
Dennis Hwang, art director of Niantic Inc.
There was a slight hitch in the morning when the game was unavailable for download, but that was soon cleared up.
"Pokemon Go officially launched its service in South Korea today. The popularity has died down but I`m going to do it." said an enthusiastic Shin Seung-woo on Facebook.
South Korea is the world`s fourth-biggest gaming market after China, the United States and Japan, according to Amsterdam-based research firm Newzoo.
In July, some impatient Pokemon fans rushed to Sokcho, a city close to the border with North Korea - an area where the game can be played as it has not been classified as South Korean territory in Google Maps data.
Nintendo`s stock was down nearly half a percent at 0430 GMT.
More about: