About 250 people have been allowed to travel from the south for three days of meetings at Mount Kumgang resort.
Another group attended reunions earlier this week.
For most of those attending it is the first time that they have had any contact in over 60 years.
Millions of people ended up separated from loved ones by the physical division of the Korean peninsula.
The reunions taking place this week are only the second round in the past five years.
One of those travelling to the resort was the mother of a man who South Korea said was abducted by the North in 1972.
The South Koreans were chosen using a computerised lottery system from among thousands who applied.
Often accompanied by family members, they travelled in a convoy of buses from South Korea to meet their relatives.
Given their age and the infrequent nature of these reunions, they are unlikely to ever see each other again.
A group of mainly elderly South Koreans have met relatives in the North, in the second of two organised reunions for family members separated by the 1950-53 Korean War.