According to Reuters news agency, officials in Seoul confirmed that the women had been freed and handed over the Red Crescent.
Witnesses said that the women were driven in a saloon car by two tribal elders to the village of Arzoo, near the city of Ghazni, where they were released.
Their release is the first good news for anxious family and friends of the hostages in South Korea since two male members of the 23-strong group were shot dead last month, after the government in Afghanistan refused to meet Taliban deadlines to free some of their militant prisoners.
The Christian aid workers were in Afghanistan as medical volunteers with the Saemmul Community Church in Bundang when they were abducted from a bus in Ghazni province more than three months ago.
The Afghan Government has so far refused to meet Taliban demands to free some of their prisoners in exchange for the Korean hostages.
Nineteen South Korean hostages remain in the hands of the Taliban, including 16 women.
