The South Korean military says a North Korean soldier defected to the South on Monday in Panmunjom, a village in the demilitarized zone between the 2 Koreas.
The Joint Chiefs of Staff says the male soldier fled a North Korean guard post to a South Korean facility called Freedom House.
The military also says the man was shot by the North Korean side, and is being treated at a hospital.
It adds that it raised the alert level against the North after the defection.
The village is jointly managed by the 2 Koreas and the United Nations command.
Inter-Korean summit talks are sometimes held there. Guided tours are available from Seoul and Pyongyang.
The demilitarized zone runs across the Korean Peninsula from west to east. Most parts are in the mountains and heavily mined.
North Korean soldiers have crossed the minefields to get to South Korea.
But defections are rare in heavily guarded Panmunjom.
There have been only 2 such cases until now -- one in 1998 and the other in 2007.