They have been reunited after being separated for over six decades as South Koreans crossed the border with the North to meet their family members.
The long-awaited emotional reunions involve around 500 South Koreans and about half as many from the North.
They had not seen each other since the Korean War in the early 1950s.
For many it will be the last chance to meet separated loved ones.
Of the 128,000 people registered in South Korea as coming from families that were torn apart by the Korean War, 44 percent have already died and more than 80 percent of the survivors are over 70, according to South Korea’s Unification Ministry, which handles inter-Korean relations.
The North had threatened to block the meetings unless South Korea suspended joint military exercises with the United States, but then backed down.
The reunions are the first since 2010 when tensions between the two Koreas spiralled.
They went ahead despite the release of a damming United Nations report on human rights abuses in North Korea.
UN investigators have said were comparable to Nazi-era atrocities.
They have said North Korean security chiefs and possibly even leader Kim Jong Un himself should face international justice.
Pyongyang has rejected the report, describing it as a concoction by the United States and its allies, Japan and the European Union.
But the North appears to be willing to maintain a rapprochement with South Korea that may be crucial as it seeks food for its people.
The possibility of looming food shortages could have been a factor.
“Now it’s almost March, when the new farming season must begin, and Kim Jong Un has no means to feed his people,” said Kim Seok-hyang, professor of North Korean studies at Ewha Womans University.
“He must get outside help. But looking around, the US won’t give him anything, China doesn’t seem willing to give anything and then there’s the UN human rights report pressuring him. The family reunions card is his last resort because he can’t neglect his people.”