The Red Cross officials from North and South Korea met as a follow-up to a summit between leaders of the two countries earlier this month.
The deal calls for a delegation of 100 people to travel to the North Korean capital Pyongyang and 100 North Koreans to visit relatives in Seoul. The visits will last four days beginning August 15, pool reports said.
A spokesman for President Kim Dae-jung praised the success of the Red Cross talks.
"The successful end of the Red Cross talks signals the landmark accord agreed between leaders of the two Koreas would be implemented in earnest," spokesman Park Joon-yung said.
Each delegation will include 30 officials and 20 reporters.
The August date marks the anniversary of the end of World War II and the Korean peninsula's liberation from Japan's 35-year occupation.
The reports said the two sides also agreed to repatriate all North Korean prisoners formerly held in the South who want to return home in early September.
Seoul freed all of the 88 North Koreans last year after long imprisonments, but they remain barred from leaving the country without government permission.
The agreement made no mention of any return of South Korean soldiers presumed still behind bars in the North despite a request for their return.
South Korean Red Cross officials proposed setting up a regular meeting point to make reunions an ongoing event, something the North Koreans agreed to discuss in September.
A North Korean official hinted the meeting point may be set up at Mount Kumgang, a resort area in the North where the Red Cross talks were held, rather than at Panmunjom, the place along their heavily-armed border where rare contacts between the two sides are traditionally arranged.
The Red Cross talks follow the first summit between the Koreas held earlier this month when South Korea's President Kim Dae-jung met North Korean leader Kim Jong-il in Pyongyang and signed a joint communique which included plans to arrange family reunions.
The reunions are a sensitive issue in South Korea, where more than one million people born in North Korea have not been able to see the families they left behind since 1953.
The two Koreas are technically still at war as the 1950-53 Korean War ended in an armed truce that remains in effect.
Family reunions have been held only once, in 1985, when 50 people from each side were allowed to meet their long-lost relatives.