Some 130 people arrived in Aweil, Northern Bahr el Ghazal from Darfur after six months of captivity.
The group made up mostly of women and children arrived in Aweil at the end of June, UNOCHA said.
They were reportedly abducted from the Kitkit/Balala area in Western Bahr el Ghazal during clashes between the South Sudan and Sudan armed forces in January.
The freed prisoners of war are being transported to their places of origin in Northern and Western Bahr el Ghazal, Warrap and Lakes states since the beginning of July.