More than 220 North Koreans have flown to South Korea from an unnamed third country for the second day running.
The refugees still have to pass tight security screening
The refugees arrived at Incheon International airport on a plane chartered by South Korea's government.
More than 200 people flew to Seoul on Tuesday, in what has become the largest single defection from the hunger-stricken Communist North.
They all apparently escaped in small groups through China to what officials called "a South East Asian country".
Seoul reportedly intervened when the country, thought to be Vietnam, threatened to send them back to China.
The plane with the latest batch of defectors landed at Incheon airport, west of Seoul, at about 0930 local time (0030 GMT).
According to South Korea's Yonhap news agency, 247 people arrived on Wednesday, to bring the total carried on the two flights to 468.
The new arrivals were then escorted to unmarked tour buses waiting inside the airport perimeter to be debriefed by officials from government security agencies, in part to ensure that there were no spies among them.
The defectors will then be given courses helping them to adapt to life in the capitalist South.
The refugees are thought to have been in Vietnam for some time, as negotiations about their future continued.
Officials in Seoul had been trying to arrange the transfer since May, after receiving complaints from the country hosting the refugees, according to the South Korean media.
In theory, South Korea still encourages defectors to leave the communist North, but it has been trying to improve ties with Pyongyang and is anxious not to antagonise the leadership there.
The South has been accepting more than 1,000 people a year from North Korea, who generally have been arriving in far smaller groups of three or four.
The number of refugees has been grown steadily in recent years, with 760 North Koreans arriving in the first six months of 2004, according to official figures.
The two Koreas technically remain at war since the bitterly-fought 1950-53 conflict ended in a truce not a peace treaty.
Their border remains tightly sealed along the Demilitarized Zone, guarded by some two million troops on both sides.