Several years ago UNESCO set itself a target of getting every child in the world in school by 2015.
The organisation now admits that goal will not be reached, with 57 million children out of education in 2011.
Sub-Saharan Africa accounts for about 30 million children.
Nigeria has the worst record, with more than 10 million children out of school in 2010.
Al Jazeera's Ahmed Idris reports from northern Nigeria.