It was by far the largest such airlift of child soldiers ever undertaken.
The children were evacuated from frontline areas in Bahr-el-Gazal province where government soldiers and the rebel Sudan People's Liberation Army frequently clash.
Under an agreement made with UNICEF head of the charity, Carol Bellamy, after she visited the area last October, the children - all boys aged eight to 18 - were taken to UN Children's Fund transit camps around Rumbek, 250 miles to the south-east. It is hoped the boys will start school and gradually be reunited with their families.
Carol Bellamy said on Tuesday in Geneva: "There's a growing recognition worldwide that children should not be in combat zones. But 300,000 (worldwide) are still being used as soldiers, porters and sex slaves. Only a global movement can make this stp."
Elijah Malok, a senior rebel official in the region, said that about 30 percent of SPLA forces were children. Many are orphans who have tagged along with the rebels and live in their camps where they are fed and cared for in return for carrying out chores such as collecting firewood and cooking. Mr Malok estimated that only 5 to 7 per cent of the children actually fought.
Most of the children fled to the rebel camps after their parents were killed or taken away as slaves.
The SPLA, the main rebel group in southern Sudan, has been fighting since 1983 to free the largely Christian south from the predominantly Muslim north.
"I am happy to be out of the barracks," said Deng Ghol, a 13-year-old who has been living with the rebels for six years. His father was killed in 1994, and Arab raiders abducted his mother.
"I am very happy I am going to have education. I hope it will help me trace my abducted mother," he said.